c plants and photosynthesis unit guide -...

Where this unit fits in Prior learning

Sheet 1 of 1© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.

C Unit guidePlants and photosynthesis

This unit builds on: 7D Variation and classification and 7C Environment and feeding relationships.

The concepts in this unit are: the role of the leaf in photosynthesis, the importance of photosynthesis to humans and other animals.

This unit leads onto:unit 9D Plants for food and to work in key stage 4 on limiting factors in photosynthesis, energy transferthrough an ecosystem and the mineral requirements of plants.

This unit relates to:7I Energy resources, 8A Food and digestion, 8B Respiration, 8D Ecological relationships, 8F Compoundsand mixtures, 9G Environmental chemistry and 9H Using chemistry.

To make good progress, pupils startingthis unit need to understand:• how organisms are sorted into groups

based on features in common• the basic structure of plants• the conditions that plants need to

grow well• that green plants take in water

through their roots and that the leafplays a part in photosynthesis

• that respiration releases CO2.

Framework yearly teaching objectives – Cells• Describe photosynthesis and the requirement of chlorophyll, light, carbon dioxide and water; know that plant nutrition involves photosynthesis and

other nutrients obtained from the soil; use this to explain:– photosynthesis as a source of biomass; – that these other nutrients, used to produce proteins and other substances, can be supplied by

fertilisers; – how leaves and roots are adapted to their functions; – conditions in which plants grow well.• Distinguish between photosynthesis and respiration in plants, including the use of word equations.

Expectations from the QCA Scheme of Work At the end of this unit …

… most pupils will … … some pupils will not have madeso much progress and will …

… some pupils will haveprogressed further and will …

in terms of scientific enquiry NC Programme of Study Sc1 1a, c, 2b, d, g, i, j, k, l, m

• identify variables relevant to an investigation of photosynthesis andsuggest how these might be controlled

• make observations and measurements using an appropriate technique, anduse measurements to produce a graph

• explain patterns in graphs using scientific knowledge and understanding.

• suggest how to control variablesidentified for them in aninvestigation of photosynthesis

• make appropriate observations andmeasurements and produce a graph.

• relate findings about theproduction of oxygen inphotosynthesis to widerenvironmental issues, e.g.seasonal changes.

in terms of life processes and living things NC Programme of Study Sc2 1e, 2k, 3a, b, c, d, e, 4a, 5a, c

• identify carbon dioxide from the air and water as the raw materials, andlight as the energy source, for photosynthesis

• explain photosynthesis as the source of biomass and representphotosynthesis by a word equation

• describe how leaves are adapted for photosynthesis and how roots areadapted to take in water

• distinguish between photosynthesis and respiration in plants.

• identify carbon dioxide from the airand water as the raw materials forphotosynthesis

• recognise that plants take in waterthrough their roots and thatphotosynthesis takes place inleaves.

• describe how cells in the leafand root are adapted forphotosynthesis and for takingin water

• represent photosynthesis as asymbol equation

• describe the relationshipbetween photosynthesis andrespiration in plants.

Suggested lesson allocation (see individual lesson planning guides)Direct route

C1Hungry plants

C2A food factory

C3Don’t dry up!

C4Using plantbiomass

C5Spot thedifference

Booster 1Focus on cells –From cells to organs

Extra lessons (not in Pupil book)

C1 Hungry plantsExtra lesson forActivity C1a.

Review and assessprogress (distributedappropriately)

MisconceptionsPupils often believe that: plants photosynthesise but do not respire; breathe in carbon dioxide and breathe out oxygen; only respire at night.

Additional informationEmphasise that plants need food for respiration just like animals. Animals and plants are different because animals eat their food, whereas plantsmake theirs.

Health and safety (see activity notes to inform risk assessment)Risk assessments are required for any hazardous activity. In this unit pupils carry out a test for starch in which a flammable liquid is heated. Theyalso plan and carry out an investigation into photosynthesis in pondweed.

A-C-Unit Guides.qxd 22-Jun-04 4:20 PM 3


C1Lesson planning

guideHungry plants

Learning objectivesi Green plants use carbon dioxide and water from the environment around the plant to produce glucose and oxygen.ii Understand that photosynthesis is the process of producing biomass.iii Light is needed for photosynthesis.iv Represent photosynthesis by a word and/or symbol equation.

Scientific enquiryv Identify and control for relevant variables in an investigation. (Framework YTO Sc1 9b)vi How ideas about plant growth have changed. (Framework YTO Sc1 9a)

Suggested alternative starter activities (5–10 minutes)

Introduce the unit

Unit map for Plants andphotosynthesis.

Share learning objectives

• Describe what photosynthesis is.• Identify and control for relevant

variables in an investigation. (Sc1)• Explain how ideas about plant

growth have changed. (Sc1)

Word game

Pupils do true/false quiz to reveal priorknowledge aboutphotosynthesis.

Brainstorming (1)

Pupils suggest where aplant gets its food.

Brainstorming (2)

Pupils identify differencesbetween a plant on awindowsill and a plantgrowing normally in themiddle of the room.

Suggested alternative plenary activities (5–10 minutes)

Review learning

Pupils fill in a template‘cooking recipe’ forphotosynthesis.

Sharing responses

Collate results andconclusions from ActivityC1a or C1b aboutphotosynthesis.

Group feedback

In small groups, pupilsdiscuss answers fromActivity C1c.

Word game

In small groups, pupilsprepare four questionsabout the lesson’s contentto ask another group.

Looking ahead

In pairs, pupils suggest howplants get the reactants forphotosynthesis to theirleaves.

Learning outcomes

Most pupils will ...

• identify the sources of raw materials in photosynthesis• explain the term photosynthesis• provide some evidence that plants do not obtain ‘food’

from the soil• write the word equation for photosynthesis• identify variables relevant to an investigation of

photosynthesis and suggest how these might becontrolled.

Some pupils, making less progress will ...

• identify the raw materials forphotosynthesis

• state that plants make their own foodwhen it is daylight

• suggest how to control variablesidentified for them in an investigation ofphotosynthesis.

Some pupils, making more progress will ...

• write the symbol equation forphotosynthesis

• identify that carbon dioxide levels arelower in the daylight because leaves areusing carbon dioxide in photosynthesis.

Key wordsphotosynthesis, reactants, products

Out-of-lesson learningHomework C1Textbook C1 end-of-spread questionsActivity C1a

Suggested alternative main activitiesActivity

Textbook C1

Activity C1a Practical

Activity C1b Practical

Activity C1c Paper

Activity C1dCatalyst InteractivePresentations 3

Learningobjectivessee above

i, ii, iii, ivand vi

i, ii, iii andiv

i, ii, iii andiv

i, iv and v

i, iii and iv

Description

Teacher-led explanation and questioning OR Pupils workindividually, in pairs or in small groups through the in-textquestions and then onto the end-of-spread questions if time allows.

What do plants need for photosynthesis? Pupils test leaves forstarch to find out if a plant needs light and carbon dioxide forphotosynthesis.

What gas is made in photosynthesis? Pupils identify the gasproduced in photosynthesis.

Gases in the greenhouse Pupils analyse data about gas levels in agreenhouse.

Support animation about photosynthesis, allowing you to remove or introduce ingredients and look at the effect onphotosynthesis.

Approx.timing

20 min

50 min

30 min over2 lessons

20 min

25 min

Target group

C H E S

R/G G R S

✔ ✔

✔

✔

✔

A-C-Unit Guides.qxd 22-Jun-04 4:20 PM Page 14


C2Lesson planning

guideA food factory

Learning objectivesi Chlorophyll and light are needed for photosynthesis.ii Leaves are adapted to photosynthesise efficiently.iii How leaf cells are specialised for photosynthesis.

Scientific enquiryiv Make systematic observations with appropriate precision. (Framework YTO Sc1 9d)v Describe patterns in graphs, using scientific knowledge to interpret them. (Framework YTO Sc1 9f)


Recap last lesson

Pupils list the products andreactants of photosynthesis.

Share learningobjectives

• Describe why plants needchlorophyll and light tophotosynthesise.

• Explain why leaves aregood at photosynthesis.

• Identify patterns in thedata, and drawconclusions. (Sc1)

Word game

Pupils play Snap! with cardsshowing different cell typesand cards with theirspecialisations, to remindthem of how cells arespecialised to theirfunction.

Brainstorming (1)

In groups, pupils draw aplant cell and label as manyfeatures as they canremember.

Brainstorming (2)

Show pupils a photo of asolar panel and discuss howit is suited to its purpose.Catalyst InteractivePresentations 3


Review learning

Pelmanism game matchingleaf parts to functions.

Sharing responses

Ask pupils to suggest whatwill happen in Activity C2a.

Group feedback

Pupils share ideas about therole of each part of the leaffrom Activity C2b.

Word game

Word splat to checkprogress on leaf structures.

Looking ahead

Pupils discuss word pairs.

Learning outcomes


• detect the presence of starch in a photosynthesisingleaf and relate it to the presence of chlorophyll

• describe how the leaf is specialised for photosynthesisand identify some differences between leaf cells

• use a range of evidence to investigate the effect oflight intensity on photosynthesis and growth.


• describe some ways in which leaf shapeand size can be specialised forphotosynthesis

• describe how to test for starch in leaves• use a simulation to investigate the effect

of light intensity on photosynthesis.

Some pupils, making more progresswill ...

• describe differences between leaf cells,explaining how the palisade cells arespecialised for photosynthesis

• explain how the rate of production ofoxygen varies with light intensity

• use graphs to show how plant growthvaries with time, identifying andexplaining anomalous results.


Textbook C2

Activity C2a ICT


Activity C2cCatalyst InteractivePresentations 3


i, ii and iii

i, iv and v

i, ii and iii

i, iv and v

Description

Teacher-led explanation and questioning OR Pupils workindividually, in pairs or in small groups through the in-textquestions and then onto the end-of-spread questions if time allows.

When do plants grow fastest? Demonstration using datalogging to compare the growth of seedlings by day and by night.

Looking at leaves Pupils look at pre-prepared leaf slides toreinforce the structure and function of a leaf.

Support animation of bubbling pondweed with variable lightintensity (and other variables for extension students) to investigateeffect of light on photosynthesis.

Approx.timing

20 min

45 min over2 lessons

30 min

25 min

Target group

C H E S

R/G G R S

✔

✔

✔

Key wordspalisade cell, chlorophyll, chloroplasts, stomata, red only: specialised,diffuse

Out-of-lesson learningHomework C2Textbook C2 end-of-spread questions



C3Lesson planning

guideDon’t dry up!

Learning objectivesi Roots are adapted to take in water and nutrients.ii Plants use water in many ways, including photosynthesis.iii Roots need oxygen for respiration.iv Plants need nutrients which are dissolved in water.

Scientific enquiryv Make careful observations and record these in drawings. (Framework YTO Sc1 9e)


Recap last lesson

Pupils list five features of aleaf that make it good atphotosynthesis.


• Describe how roots take inwater and nutrients fromthe soil.

• Describe how plants usewater for various reasons.

• Draw biological specimensusing a microscope. (Sc1)

Word game

Pupils play a true/false quizby showing cards.

Problem solving

Show pupils a daffodil thathas been standing in blueink for 24 hours. In pairs,ask pupils to discuss andsuggest one idea for whythe petals have turned blue.

Capture interest

Show pupils photos of aplant that has been under-watered and a plant thathas been over-watered.Catalyst InteractivePresentations 3


Textbook C3

Activity C3a Practical




i, ii, iii andiv

i and v

i, ii and iv

i, ii and iv

Description

Teacher-led explanation and questioning OR Pupils work individually,in pairs or in small groups through the in-text questions and thenonto the end-of-spread questions if time allows.

Looking at root hairs Pupils look at pre-prepared slides of root toreinforce their knowledge of structure and function.

Water transport in celery Pupils view coloured water in plant veinsto reinforce their understanding of the structure and function ofveins in plants.

Support simulation to build up pupils’ understanding of the route bywhich water moves from roots to leaves, and by which glucose movesfrom leaves to the other parts of the plant.

Approx.timing

20 min

30 min

20 minover 2 lessons

15 min

Target group

C H E S

R/G G R S

✔

✔

✔


Review learning

As a class, draw a flowchart of water movement ina plant on the board.

Sharing responses

Collate results andconclusions from Activity C3b.

Group feedback

Share ideas from ActivityC3a about how root hairshelp the plant take in waterand nutrients from the soil.

Word game

Loop game onphotosynthesis to checkprogress.

Looking ahead

As a class, discuss why acarrot root is swollen withstored food, rather thanbeing branched and thin.

Learning outcomes


• explain the functions of water and nutrients in plants• explain how roots are specialised to take in water• describe how a root hair cell is specialised for its

function• in response to a variety of evidence, work out how

water is transported through a plant• use a microscope safely to make careful observations

of root hairs.


• describe some of the functions of waterand nutrients in plants

• describe some of the ways in whichroots are specialised to take in water

• use a simulation to describe the routetaken by water and glucose through aplant.


• explain how a root hair cell is specialised forits function

• explain why plants in waterlogged soil willdie, even though they have ample water andminerals.

Key wordsfertiliser, nutrients, root hair, root hair cell, surface area, veins

Out-of-lesson learningHomework C3Textbook C3 end-of-spread questionsPupils investigate the ingredients of fertiliser from the Internet, and find out what each component is used for by the plant.



C4Lesson planning

guideUsing plant biomass

Learning objectivesi Plants store starch.ii New materials made from glucose produced in photosynthesis lead to an increase in biomass.iii Glucose from photosynthesis provides energy for all living processes in the green plant.iv Understand the meaning of the term biomass.

Scientific enquiryv Identify relevant information and use different texts as sources. (Framework YTO Sc1 8d)


Recap last lesson

Give pupils the list ofanswers. Ask them to workin pairs to devise questionsfor each of these answers.


• Describe how plants useglucose.

• Describe what biomass is.• Select relevant

information from differentwebsites. (Sc1)

Problem solving

In groups, pupils identifyphotos of a range of storageorgans as fruit, stem, rootor leaf.Catalyst InteractivePresentations 3

Brainstorming

Pupils list five things thatare made of plants in theirhouse.

Word game

Pupils complete thewordsearch to findcomponents of a plant’sbiomass (protein, cellulose,etc.).


Textbook C4

Activity C4a ICT

Activity C4b Paper



i, ii, iii and iv

ii, iii, iv andv

i, ii, iii andiv

i and ii

Description


Products from biomass Pupils research which plant biomasssubstances are used to make useful products.

What fuel? Pupils calculate the energy content of various foods tosee which would be suitable to use as a fuel.

Interactive animation in which pupils fit glucose molecules into thecorrect positions to build up sucrose, cellulose and starch.

Approx.timing

20 min

30 min

20 min

10 min

Target group

C H E S

R/G G R S

✔ ✔

✔

✔ ✔


Review learning

Play ‘What happens next?’starting fromphotosynthesis happeningin a tree.

Sharing responses

Share findings from Activity C4a to produce atable on the board of allthe group’s results.

Group feedback

In groups, pupils collateresults and conclusions fromActivity C4b.

Word game

Pupils write a spiderdiagram to show howphotosynthesis relates tothe production of biomass.

Looking ahead


Learning outcomes


• identify photosynthesis as the source of biomass in plantsand describe ways in which humans use plant biomass

• explain that glucose made in photosynthesis is used forrespiration

• select, compare and synthesise information from differentwebsites to describe some ways in which humans use plantbiomass.


• identify some ways in which humansuse plant biomass

• explain that glucose made inphotosynthesis is used for energy, andcan be stored.


• find out about the molecular structuresof glucose and starch, appreciating therelationship between them.

Key wordsNone

Out-of-lesson learningHomework C4Textbook C4 end-of-spread questions



C5Lesson planning

guideSpot the difference

Learning objectivesi Photosynthesis removes carbon dioxide from the air and produces oxygen.ii Distinguish between photosynthesis and respiration.iii Compare the word equations for photosynthesis and respiration.iv Deforestation can have a range of local and global effects on ecosystems.

Scientific enquiryv Relate respiration and photosynthesis to wider environmental issues and effects of scientific and technological developments.

(Framework YTO Sc1 9a)vi Consider issues of environmental protection from several perspectives.


Recap last lesson

Play ‘What am I?’ focusingon products of plantbiomass.


• Describe how photosynthesisand respiration affectoxygen and carbon dioxidelevels in the air.

• Explain how cutting downforests can affect climateand living things.

• Recognise problems ofenvironmental protectionfrom different perspectives. (Sc1)

Problem solving

Use flashcards to rearrangethe reactants and productsof photosynthesis to remindpupils of the word equation.

Word game

In groups, pupils fill in thespeech bubbles for theconcept cartoon in responseto the problem ‘Ifphotosynthesis uses upcarbon dioxide, why doesthe total amount of carbondioxide in the atmospherealways stay the same?’

Capture interest

Play hangman to coverspelling of photosynthesis,respiration, chlorophyll, anddeforestation.


Textbook C5

Activity C5a ICT

Activity C5bICT


i, ii, iii andiv

iv, v and vi

i, ii and iii

Description


Dangers of deforestation Pupils produce a leaflet about the effectsof deforestation.

Maintaining the balance Pupils monitor oxygen and carbon dioxidelevels in a plant over 24 hours using ICT.

Approx.timing

20 min

35 min

20 min

Target group

C H E S

R/G G R S

✔

✔


Review learning

Pupils reorganisestatements aboutphotosynthesis into thecorrect order.

Sharing responses

Collate results andconclusions from Activity C5b.

Group feedback

Pupils swap leaflets createdfrom Activity C5a andevaluate them.

Word game

Complete a mind map,showing howphotosynthesis andrespiration are related.

Looking back

Pupils revise andconsolidate knowledge fromthe unit.

Learning outcomes


• explain how photosynthesis and respiration can helpmaintain the balance of gases in the air

• describe how carbon dioxide and oxygenconcentrations in the air have varied over time

• identify the advantages and disadvantages of forestconservation for a range of people and living things.


• explain that animals use oxygen releasedfrom photosynthesis

• be aware of some of the advantages anddisadvantages of forest conservation for arange of living things.


• investigate the social and environmentalissues relating to forest conservation for a range of people and living things, inparticular considering the consequences of logging.

Key wordsNone

Out-of-lesson learningHomework C5Textbook C5 end-of-spread questionsRead about forest clearance and the consequent loss of biodiversity


C Unit mapPlants and photosynthesis


Copy the unit map and use these words to help you complete it.You may add words of your own too.

carbon dioxidechlorophyllchloroplastsdiffuse Renergyfertiliserglucoseguard cells Rlight energynutrientsoxygenpalisade cellphotosynthesis

productsreactantsrespirationroot hairroot hair cellspecialised RstarchstomatastoreSunsurface areaveinswater

Photosynthesis

How plantsmake food

Plants and theenvironment

Biomass

Roots

Leaves

Unitmaps.qxd 18-Jun-04 11:36 AM Page 3


C1 StartersHungry plants

Introduce the unit� Either draw the outline of the unit map on the board

then ask pupils to give you words to add, saying where toadd them. Suggest some words yourself when necessaryto keep pupils on the right track.

� Or give out the unit map and ask pupils to work ingroups deciding how to add the listed words to thediagram. Then go through it on the board as each groupgives suggestions.

Share learning objectives� Ask pupils to write a list of FAQs they would put on a

website telling people about plants and photosynthesis.Collect suggestions as a whole-class activity, steeringpupils towards those related to the objectives. Concludeby highlighting the questions you want them to be ableto answer at the end of the lesson.

Word game� Give out the true/false quiz sheets for pupils to complete

quickly, revealing aspects of their prior knowledge.

Brainstorming (1)� Show pupils a plant in a pot, and ask ‘Where does a plant

get its food?’.

� In groups, ask pupils to list as many ideas as they can.

Brainstorming (2)� Show pupils a plant that has been growing on a

windowsill, and one that has been growing in themiddle of the room (away from any windows).

� As a class, discuss what the differences are. If thereis time, ask them to explain the differences.

➔ Unit map

➔ Pupil sheet

Answers1 false; 2 false; 3 true; 4 true; 5 true; 6 true; 7 true

Equipmentpot plant

Equipmentpot plant growing on a windowsill for atleast a week; pot plant growing in alocation with light all around

AnswersPupils should notice that the plant on thewindowsill has bent over towards thelight. They may also notice that it becametaller more quickly than the other one.


Introduce the unit

Unit map for Plantsand photosynthesis


• Describe what photosynthesis is.• Identify and control for relevant

variables in an investigation. (Sc1)• Explain how ideas about plant

growth have changed. (Sc1)

Word game

Pupils do true/false quizto reveal prior knowledgeabout photosynthesis.

Brainstorming (1)

Pupils suggest where aplant gets its food.

Brainstorming (2)

Pupils identify differencesbetween a plant on awindowsill and a plantgrowing normally in themiddle of the room.

C-Starters.qxd 07-Jun-04 12:04 PM Page 1

C1 Starters

Sheet 1 of 1

Sheet 1 of 1

© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.

StartersC1 Hungry plants

Word game

Decide if the following statements are true or false.

1 Plants get all their food from the soil. [True/False]

2 Plants take in water through their leaves. [True/False]

3 Plants need light to survive. [True/False]

4 Plants make their own food. [True/False]

5 Plants’ roots hold them firmly in the soil. [True/False]

6 Plants need oxygen to survive. [True/False]

7 Plants need carbon dioxide to survive. [True/False]


Hungry plants

Word game

Decide if the following statements are true or false.

1 Plants get all their food from the soil. [True/False]

2 Plants take in water through their leaves. [True/False]

3 Plants need light to survive. [True/False]

4 Plants make their own food. [True/False]

5 Plants’ roots hold them firmly in the soil. [True/False]

6 Plants need oxygen to survive. [True/False]

7 Plants need carbon dioxide to survive. [True/False]



C2 StartersA food factory

Recap last lesson� Ask pupils to list the products and reactants of

photosynthesis.


website telling people about leaves and photosynthesis.Collect suggestions as a whole-class activity, steeringpupils towards those related to the objectives. Concludeby highlighting the questions you want them to be ableto answer at the end of the lesson.

Word game� Ask pupils to play Snap! in pairs, using the cards on the

pupil sheet to match cell type with its adaptations.

Brainstorming (1)� In groups, pupils draw a plant cell and label as many

features as they can remember.

� Pupils should swap their drawings with other groups,and then write down what is missing and correct whatis wrong.

Brainstorming (2)� Show pupils a photograph of a solar panel, discuss its

purpose and how a solar panel is well suited to it.

➔ Pupil sheet

➔ Catalyst Interactive Presentations 3


Recap last lesson

Pupils list the products andreactants of photosynthesis.


• Describe why plants needchlorophyll and light tophotosynthesise.

• Explain why leaves aregood at photosynthesis.

• Identify patterns in thedata, and drawconclusions. (Sc1)

Word game

Pupils play Snap! with cardsshowing different cell typesand cards with theirspecialisations, to remindthem of how cells arespecialised to theirfunction.

Brainstorming (1)

In groups, pupils draw aplant cell and label as manyfeatures as they canremember.

Brainstorming (2)

Show pupils a photographof a solar panel, discuss itspurpose and how a solarpanel is well suited to it.Catalyst InteractivePresentations 3


C2 StartersA food factory

Word game


red blood cell has a tail to swim with

large size to store food

changes shape to allow gases in and out

contains chloroplasts to catch light

flexible to make it fit through small blood vessels and contains

haemoglobin to carry oxygen

palisade cell

sperm cell

egg cell

guard cell



C3 StartersDon’t dry up!

Recap last lesson� Pupils list five features of a leaf that make it good at

photosynthesis.

� Ask individuals to suggest one feature and write it on theboard until there is a full list as a summary for all to writedown.


website telling people about water and plants. Collectsuggestions as a whole-class activity, steering pupilstowards those related to the objectives. Conclude byhighlighting the questions you want them to be able toanswer at the end of the lesson.

Word game� Make a set of cards (true, false, unsure) for each pupil

from the teacher sheet (you could use a different colourcard for each word).

� Read out the statements on the teacher sheet. Pupils holdup the card for their answer simultaneously.

� If many pupils get an answer wrong, it may be becausethey won’t have met the ideas yet, and will need to waituntil the end of the lesson before they can get all theanswers right.

Problem solving� Show pupils a daffodil that has been standing in blue ink

for 24 hours.

� In pairs, ask pupils to discuss and suggest one idea forwhy the petals have turned blue.

� Join pairs into fours, and collate their answers to be fedback to a class discussion.

Capture interest� Show pupils photographs of a plant that has been

under-watered and a plant that has been over-watered.

� Ask pupils to describe the effect of lack of water onplants.

➔ Teacher sheet

Equipmentdaffodil left in blue ink for 24 hours



Recap last lesson

Pupils list five features of aleaf that make it good atphotosynthesis.


• Describe how roots take inwater and nutrients fromthe soil.

• Describe how plants usewater for various reasons.

• Draw biological specimensusing a microscope. (Sc1)

Word game

Pupils play true/false quizby showing cards.

Problem solving

Show pupils a daffodil thathas been standing in blueink for 24 hours. In pairs,ask pupils to discuss andsuggest one idea for whythe petals have turned blue.

Capture interest

Show pupils photographs ofa plant that has beenunder-watered and a plantthat has been over-watered.Catalyst InteractivePresentations 3


C3 StartersDon’t dry up!


Word gamePlants have tubes to carry water around their parts. [True]

Plants have a heart to pump water around their parts. [False]

Root cells don’t have any chlorophyll so they don’t need any glucose. [False]

Glucose is carried from the leaves to the roots. [True]

Plants need water to stand up straight. [True]

If roots are branched, they can take in more water. [True]

Roots do not take in any nutrients from the soil. [False]

Display the words below in large type for pupils to hold up for you to see.Make them into 2 × 4 = 8 cards to a sheet.

True TrueTrue TrueTrue TrueTrue True


False FalseFalse FalseFalse FalseFalse False


Unsure UnsureUnsure UnsureUnsure UnsureUnsure Unsure



C4 StartersUsing plant biomass

Recap last lesson� Give pupils the list of answers. Ask them to work in pairs

to devise questions for each of these answers.

Share learning objectives� Write the learning objectives on the board and show why

it is important that we know about these ideas.

� Tell pupils that plants make glucose, which is turned intolots of different substances, which are also useful tohumans.

� Give pupils examples of how biomass is useful.

Problem solving� In groups, pupils identify photographs of a range of

storage organs as fruit, stem, root or leaf.

� Go through the answers with the whole class, anddiscuss why we eat these organs.

Brainstorming� Pupils list five things that are made of plants in their

house.

� Collate pupils’ ideas into a summary list on the board.

Word game� Ask pupils to complete the wordsearch on the pupil

sheet.

� Ring the words on a copy of the pupil sheet and show itas an OHT for them to check their answers. Use thewords on it to introduce the lesson.

➔ Pupil sheet


➔ Pupil sheet


Recap last lesson



• Describe how plants useglucose.

• Describe what biomass is.• Select relevant

information from differentwebsites. (Sc1)

Problem solving

In groups, pupils identifyphotographs of a range ofstorage organs as fruit,stem, root or leaf. Catalyst InteractivePresentations 3

Brainstorming

Pupils list five things thatare made of plants in theirhouse.

Word game

Pupils complete the wordsearch to find componentsof a plant’s biomass (i.e.protein, cellulose, etc.).



Recap last lesson

1 Roots2 Water3 Nutrients4 Root hairs5 Fertiliser6 Veins

Sheet 1 of 1

Sheet 1 of 1


StartersC4 Using plant biomass

Recap last lesson



Sheet 1 of 1

StartersC4 Using plant biomass

Recap last lesson




Word game

All of these words are connected with plant biomass. See howmany you can find in the wordsearch.



sucrose glucose protein biomass

starch fat cellulose root

stem leaves fruit vegetables

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C5 StartersSpot the difference

Recap last lesson� Ask ‘What am I?’ focusing on products of plant biomass.

Remind pupils they can only ask closed questions,which can be answered yes or no. They have todetermine the answer with as few questions as possible.

Share learning objectives� Write the learning objectives on the board and show

why it is important that we know about these ideas.

� Tell pupils that photosynthesis and respiration controlthe amount of carbon dioxide in the air.

� Tell pupils that if this get unbalanced, the world’sclimate can be affected by the greenhouse effect.

� Tell pupils that cutting down rainforests could cause animbalance between oxygen and carbon dioxide.

Problem solving� Use flashcards to rearrange the reactants and products

of photosynthesis to remind pupils of the wordequation.

Word game� In groups, pupils fill in the speech bubbles for the

concept cartoon displayed as an OHT.

� Discuss as a class how carbon dioxide is released fromplants again by burning, respiration in animals and bymicrobe respiration of rotting plant material.

Capture interest� Play a game of hangman with the whole class to

reinforce vocabulary and spelling of the followingkey words.

➔ Pupil sheet

➔ Teacher sheet

Key wordsphotosynthesis; respiration; chlorophyll;deforestation


Recap last lesson

Play ‘What am I?’focusing on productsof plant biomass.


• Describe how photosynthesisand respiration affect oxygenand carbon dioxide levels inthe air.

• Explain how cutting downforests can affect climate andliving things.

• Recognise problems ofenvironmental protection fromdifferent perspectives. (Sc1)

Problem solving

Use flashcards to rearrangethe reactants and productsof photosynthesis to remindpupils of the word equation.

Word game

In groups, pupils fill in thespeech bubbles for theconcept cartoon in responseto the problem ‘Ifphotosynthesis uses upcarbon dioxide, why doesthe total amount of carbondioxide in the atmospherealways stay the same?’

Capture interest

Play hangman to coverspelling of photosynthesis,respiration, chlorophyll, anddeforestation.


Sheet 1 of 1

StartersC5 Spot the difference



Problem solving


carbon dioxide water

oxygen glucose

light energy chlorophyll

+ +

carbon dioxide water

oxygen glucose

light energy chlorophyll

+ +

Problem solving



Word game


If photosynthesis uses up carbon dioxide, why does thetotal amount of carbon dioxide in the atmosphereremain the same?


C1aTeacher

activity notesWhat do plants need forphotosynthesis?

Running the activityNB: Plants must first be left in the dark for 24 hours to destarch them. After the destarched plants havebeen set up as shown, they must be left in a light place for a further 24 hours before the experiment.

Pupils work in small groups, or the activity could be carried out as a teacher demonstration. The pupilsthen test the leaves for starch, which should take about 30 minutes. Pupils test three leaves at the sametime, cutting a shape in the side of each to identify which are leaves 1, 2 and 3. Alternatively, pupils testone leaf at a time to ensure that they don’t get them mixed up. A preheated water bath will be needed forheating the ethanol (see Safety notes below). The leaves must be completely decolourised in ethanol forpupils to see the colour change with iodine.

Core: The method is given for the activity, and pupils come up with their own format for recording results.Questions ask them to draw conclusions about what the plant needs for photosynthesis.

Help: This sheet provides a table for pupils to record their results, and more structured questions lead themto their conclusions. Instructions for the experiment are not given on this sheet, so pupils will need helpwith the activity (pupils can be given access to the core sheet for more information), or the sheet could beused to accompany a teacher demonstration.

Expected outcomesIodine will change from orange to black when starch is present in the leaf. The presence of starchindicates that the plant has been photosynthesising. Areas of leaves covered with black tape will not turniodine black, indicating that the leaf needs light for photosynthesis. Leaves kept in the presence ofsodium hydroxide will not turn iodine black, indicating that carbon dioxide is needed for photosynthesis.Leaves that have been kept in the light with carbon dioxide will turn iodine black, indicating that starchhas been produced by photosynthesis.

PitfallsThe plants must be thoroughly destarched before use, otherwise false results will be obtained. Old leavesshould be avoided. Put soda lime in the conical flasks before the start of this activity.

Safety notesEye protection required. Warn pupils that soda lime is corrosive and that iodine is harmful as well asproducing stains on skin and clothing.

Ethanol is flammable. Use a hotplate for the water bath to heat the ethanol. Do not use a naked flame toheat it. Warn pupils to take care with boiling water. If they scald themselves, cool the skin with plenty ofcold running water.

AnswersCore:

1 To test whether light is needed for photosynthesis. 2 To test whether carbon dioxide is needed forphotosynthesis. 3 A control. 4 Light is needed for photosynthesis because starch only formed in theparts of the leaf that had access to light. 5 Carbon dioxide is needed for photosynthesis because the leafwithout carbon dioxide did not make starch. 6 To destarch the leaves (so that the plant uses up any starchalready produced in the leaves).

Help:

1 Orange, blue/black, photosynthesis. 2 It turned blue/black in those areas with light, and stayed orangein the area under the tape without light. 3 Light is needed for photosynthesis. 4 No colour change.5 Carbon dioxide is needed for photosynthesis. 6 Colour changed to blue/black. 7 Starch is present, sothe leaf has been photosynthesising. 8 As a control, against which to compare leaf 1 and leaf 2, to see theeffect of removing light and carbon dioxide.


Type Purpose DifferentiationPractical Pupils test leaves for starch in order to find out whether a plant needs light and carbon

dioxide for photosynthesis.Core, Help

C-Teachers.qxd 17-Jun-04 8:33 PM Page 1

C1aTechnician

activity notesWhat do plants need forphotosynthesis?

Equipment

For your informationRunning the activityNB: Plants must first be left in thedark for 24 hours to destarch them.After the destarched plants have beenset up as shown, they must be left ina light place for a further 24 hoursbefore the experiment.

Pupils work in small groups, or the activity could be carried out as a teacher demonstration. The pupils testthe leaves for starch, which should take about 30 minutes. Pupils test three leaves at the same time, cuttinga shape in the side of each to identify which are leaves 1, 2 and 3. Alternatively, pupils should test one leafat a time to ensure that they don’t get them mixed up. A preheated water bath will be needed for heatingthe ethanol (see Safety notes below). The leaves must be completely decolourised in ethanol for pupils tosee the colour change with iodine.

Core: The method is given for the activity, and pupils come up with their own format for recording results.Questions ask them to draw conclusions about what the plant needs for photosynthesis. Question 4 couldbe used as an extension question.

Help: This sheet provides a table for pupils to record their results, and more structured questions lead themto their conclusions. Instructions for the experiment are not given on this sheet, so pupils will need helpwith the activity (pupils can be given access to the core sheet for more information), or the sheet could beused to accompany a teacher demonstration.

Expected outcomesIodine will change from orange to black when starch is present in the leaf. The presence of starch indicatesthat the plant has been photosynthesising. Areas of leaves covered with black tape will not turn iodineblack, indicating that the leaf needs light for photosynthesis. Leaves kept in the presence of sodiumhydroxide will not turn iodine black, indicating that carbon dioxide is needed for photosynthesis. Leavesthat have been kept in the light with carbon dioxide will turn iodine black, indicating that starch has beenproduced by photosynthesis.

PitfallsThe plants must be thoroughly destarched before use, otherwise false results will be obtained. Old leavesshould be avoided. Put soda lime in the conical flasks before the start of this activity.

Safety notesEye protection required. Warn pupils that soda lime is corrosive and that iodine is harmful as well asproducing stains on skin and clothing.

Ethanol is flammable. Use a hotplate for the water bath to heat the ethanol. Do not use a naked flame toheat it. Warn pupils to take care with boiling water. If they scald themselves, cool the skin with plenty ofcold running water.


Type Purpose DifferentiationPractical Pupils test leaves for starch in order to find out whether a plant needs light and carbon

dioxide for photosynthesis.Core, Help

leaf 1black tape (thisstops the light)

leaf 2soda lime (thisremoves all thecarbon dioxide)

plant has been left indarkness for 24 hours

For the class:

� hotplates for heating water baths

For each group:

� destarched plant, e.g. geranium� black tape

� conical flask containing soda lime� split bung to fit around leaf stalk� clamp stand and clamp� forceps� scalpel and cutting tile (optional)� Bunsen burner� heatproof mat� tripod and gauze

� beaker (250 cm3)� boiling tube� tube holder� ethanol� white tile� iodine dropper bottle� paper towel

C-Technician.qxd 18-Jun-04 11:51 AM Page 1

C1aActivity

CoreWhat do plants need forphotosynthesis?

In photosynthesis, plants make sugars which they store as asubstance called starch. If you find starch in a plant’s leaves, youknow it has been carrying out photosynthesis. You are going totest whether leaves can carry out photosynthesis without sunlight,and without carbon dioxide.

Obtaining evidence1 Set up the plant as shown in the diagram.

1 What is leaf 1 testing for?2 What is leaf 2 testing for?3 You are going to take a third, untreated leaf (leaf 3), from the

plant. What is the purpose of this leaf?

2 Take leaves 1 and 2 off the plant. Also take one more leaf(leaf 3), which is untreated. Make sure you remember whichleaf is which! You can do this by cutting a different shape outof the side of each leaf and noting which leaf has which shape.

3 Using forceps, place the leaves in 50 cm3 of boiling water ina beaker. After 2 minutes, turn off the Bunsen burner.

4 Take the leaves out of the water and soak them in a boilingtube of warm ethanol in a water bath until they gocolourless, as shown.

5 Dip the leaves in cool water, spread them out on a white tileand test them with a few drops of iodine. This turns fromorange to black if there is starch present.

Presenting the results6 Record the results of the starch test for each leaf.

Considering the evidence4 What do the results for leaf 1 tell you about photosynthesis?5 What do the results for leaf 2 tell you about photosynthesis?6 Why do you think the leaves were kept in the dark for 24 hours

before the start of the experiment?


leaf 1black tape (thisstops the light)

leaf 2soda lime (thisremoves all thecarbon dioxide)

plant has been left indarkness for 24 hours

boilingwater

hot waterethanol

Wear eyeprotection.

Ethanol isflammable.Do not use a

Bunsen burner near it.

Soda lime is corrosive;avoid all contact.

Take care with boilingwater.

Iodine solution isharmful. It can stainyour skin and yourclothes.

C-Activities.qxd 18-Jun-04 9:39 AM Page 1

C1aActivity

HelpWhat do plants need forphotosynthesis?

Use this sheet to record your results and conclusions.

Obtaining evidence

Work in groups of three. There are three leaves to test for starch.Test one leaf each.

Presenting the results

1 Record your results in the table below.

Considering the evidence

Complete these sentences.

1 Iodine solution will change from to

if starch is present in the leaf. If starch is present in the leaf, it means

the leaf has been carrying out

2 What happened to the iodine on leaf 1?

3 What does this tell you about photosynthesis in leaf 1?





8 What was the purpose of leaf 3 in the experiment?


Leaf Colour change

Leaf 1 (black tape – no sunlight)

Leaf 2 (sodium hydroxide solution – no carbon dioxide)

Leaf 3

Wear eyeprotection.

Ethanol isflammable.Do not use a

Bunsen burner near it.

Soda lime is corrosive;avoid all contact.

Take care with boilingwater.

Iodine solution isharmful. It can stain yourskin and your clothes.


C1bTeacher

activity notesWhat gas is produced byphotosynthesis?

Running the activityNB: This activity needs to be run over two lessons.

The pupils work in groups, or the activity can be run as a teacher demonstrationto save time. Pupils are instructed to set up the experiment and leave it until thenext lesson on a windowsill. The gas that has collected the next day is tested with a glowing splint, or the gas can be produced more quickly by shining a lamp on the plant. Questions lead pupils to draw conclusions and analyse theexperiment.

Expected outcomesThe glowing splint will be relit, showing that the gas that is produced by thephotosynthesising plant is oxygen.

Safety notesPupils should take care with the Bunsen burners.

PitfallsIt is often difficult to collect a substantial enough amount of oxygen for theglowing splint test. Be prepared to use an oxygen cylinder to prepare a tube ofoxygen to put over the pond weed before students arrive.

ICT opportunitiesIt should be possible to set up a datalogging experiment to observe fluctuationsin the rate of photosynthesis by measuring the concentration of oxygen inwater surrounding pond weed over 24 hours.

Answers1 oxygen

2 e.g. shine a bright light on the plant throughout the 24-hour period; growthe plant in an enriched atmosphere of carbon dioxide.

3 food/sugars/glucose


Type Purpose DifferentiationPractical Pupils observe that plants make a gas during photosynthesis and test the gas to find

out whether it is oxygen.Core


C1bTechnician

activity notesWhat gas is produced byphotosynthesis?

EquipmentFor each group (or teacher demonstration):

� water plant, e.g. pond weed� glass funnel� Plasticine to support funnel in beaker� beaker (250 cm3)� test tube� splint� Bunsen burner� heatproof mat� lamp (optional)

For your informationRunning the activity

NB: This activity needs to be run over two lessons.

The pupils work in groups, or the activity can be run as a teacher demonstrationto save time. Pupils are instructed to set up the experiment and leave it until thenext lesson on a windowsill. The gas that has collected is tested with a glowingsplint, or the gas can be produced more quickly by shining a lamp on the plant.Questions lead pupils to draw conclusions and analyse the experiment.

Expected outcomesThe glowing splint will be relit, showing that the gas that is produced by thephotosynthesising plant is oxygen.

Safety notesPupils should take care with the Bunsen burners.

PitfallsIt is often difficult to collect a substantial enough amount of oxygen for theglowing splint test. Be prepared to use an oxygen cylinder to prepare a tube ofoxygen to put over the pond weed before students arrive.


Type Purpose DifferentiationPractical Pupils observe that plants make a gas during photosynthesis and test the gas to find

out whether it is oxygen.Core

1

waterfunnelpond weed

plasticine support


C1bActivity

CoreWhat gas is made inphotosynthesis?

A plant uses carbon dioxide and water to make food byphotosynthesis. You are going to find out what else is madeduring photosynthesis. You are going to collect a gas from aplant and test it with a glowing splint. If the splint relights,the gas is oxygen.

Obtaining evidence

1 Set up the beaker as shown in the diagram.2 Fill the test tube with water. Put your thumb over the

end then turn the test tube upside down. Take carethat no air gets in the test tube.

3 Carefully lower the test tube into the beaker so the endyou are holding is under the water above the funnel.

4 Remove your thumb and lower the test tube over the end of the funnel.

5 Leave the beaker on a windowsill until the next lesson.6 Next lesson, take a splint and blow it out so that it is

glowing.7 Slide your thumb over the end of the test tube under

the water, then remove the test tube carefully. Turn theright way up.

8 Taking care not to let all the collected gas escape,quickly remove your thumb and place the glowingsplint inside the test tube.

9 Record what happens to the splint.


1 What gas was produced during this experiment?2 Think about how you might be able to make the plant

produce the gas faster. Suggest ways you might try.3 What else is produced by photosynthesis?


2

3

4, 5

sunlight

8

1

waterfunnelpond weed

plasticine support

Take carewith Bunsenburners.


C1cTeacher

activity notesGases in the greenhouse

Running the activityThis activity involves pupils analysing graphs to make conclusions aboutphotosynthesis. It asks pupils to think about the effects of changing gas levelson plants in a greenhouse, and leads them into thinking about limiting factors.

Answers1 yes

2 Because carbon dioxide is a reactant of photosynthesis, giving a plant morecarbon dioxide will make it photosynthesise more.

3 no

4 Oxygen is not a reactant in photosynthesis.

5 Light, water.

6 If you increased the amount of water and light as well, the speed ofphotosynthesis would increase, showing that these factors were previouslyin short supply.


Type Purpose DifferentiationPaper Pupils analyse data about gas levels in a greenhouse, applying their knowledge about

photosynthesis.Extension


C1cActivity

ExtensionGases in the greenhouse

Jack knows that plants need carbon dioxide and oxygen tosurvive. He wondered if he could increase the speed ofphotosynthesis by increasing the amount of carbon dioxideand oxygen available to the plants in his aquarium. Hemeasured the speed of photosynthesis by counting thebubbles coming off his plants.

1 Was the increase in speed ofphotosynthesis affected by anincrease in the amount ofcarbon dioxide available?

2 Explain your answer to question 1.3 Was the increase in speed of

photosynthesis affected by anincrease in the level of oxygenavailable?

4 Explain your answer to question 3.

Look again at the graph of carbondioxide levels. When plants aresupplied with more and more carbondioxide, the increase in the speed ofphotosynthesis eventually stops.

5 Even if plants are supplied with a lot of carbon dioxide, they may beshort of other factors required forphotosynthesis. What are thesefactors?

6 Explain how you could test whichof the factors in your answer toquestion 5 really is in short supply.


Increase inspeed ofphotosynthesis

Level of carbon dioxide

Graph of speed of photosynthesis against CO2 levels

Increase inspeed ofphotosynthesis

Level of oxygen

Graph of speed of photosynthesis against O2 levels


C2aTeacher

activity notesWhen do plants grow fastest?


This activity will probably be run as a teacher demonstration unless there areenough position sensors available for each group of pupils. The growingseedlings are set up and left by a window for three days. The results are moreconvincing if the experiment can be left longer. Pupils are asked questions,leading them to a conclusion, and also to evaluate the experiment.

Other relevant materialSkill sheet 6: Interpreting graphsSkill sheet 26: Designing a spreadsheetSkill sheet 28: Calculations with a spreadsheet

Expected outcomesThe position sensor will indicate a general increase in size. There will be amarked increase in the growth of plants during the day that may be lessobvious with younger plants.

PitfallsDo not forget to water the seedlings. The position sensor connections are oftenvery delicate and easily disturbed by pupils, perhaps from other classes.

Safety notesBe aware that some seeds may be treated with fungicides and pesticides. Pupilsshould wash their hands after handling seeds or plants.

ICT opportunitiesIt would be possible to set up a spreadsheet for the results and subsequentcalculations.

Answers1 During the day, as there is more photosynthesis then.

2 During the night, as there is no photosynthesis then.

3 Doing the experiment a few times would make the results more reliable, incase a mistake was made. Using more plants would make the results morereliable, in case there was something wrong with the plants. Carrying outthe experiment for a shorter period of time would not improve theexperiment. Carrying out the experiment for a longer period of time wouldmake the results more obvious to see.


Type Purpose DifferentiationICT Demonstration using datalogging to compare the growth of seedlings during daylight

and at night. A position sensor is used to monitor the growth.Core


C2aTechnician

activity notesWhen do plants grow fastest?

Other relevant materialSkill sheet 6: Interpreting graphsSkill sheet 26: Designing a spreadsheetSkill sheet 28: Calculations with a spreadsheet

EquipmentFor the class:� computer� interface� position sensor� seedlings, e.g. of wheat growing on growth medium,

e.g. cotton wool (see tips below)� wire or arm with counterweight� cotton thread� clamp stand� printer (optional)

For your informationRunning the activityNB: This activity needs to be run over two lessons.

This activity will probably be run as a teacher demonstration unless there are enough position sensorsavailable for each group of pupils. The growing seedlings are set up and left by a window for three days.The results are more convincing if the experiment can be left longer. Pupils are asked questions, leadingthem to a conclusion, and also to evaluate the experiment.

Expected outcomesThe position sensor will indicate a general increase in size. There will be a marked increase in the growth ofplants during the day that may be less obvious with younger plants.

PitfallsDo not forget to water the seedlings. The position sensor connections are often very delicate and easilydisturbed by pupils, perhaps from other classes.

Safety notesBe aware that some seeds may be treated with fungicides and pesticides. Pupils should wash their handsafter handling seeds or plants.


Type Purpose DifferentiationICT Demonstration using datalogging to compare the growth of seedlings during daylight

and at night. A position sensor is used to monitor the growth.Core

wire or armwith small

counterweightto keep

cotton taut

position sensor

cotton

seedling

interface computer


C2aActivity

CoreWhen do plants grow fastest?

You are going to follow the growth of a plant over three daysusing datalogging equipment. You are going to use a positionsensor to find out when a plant grows the fastest.

Obtaining evidence

1 Your teacher will set up the apparatus as shown. The cotton mustbe tight.


wire or armwith small

counterweightto keep

cotton taut

position sensor

cotton

seedling

interface computer

2 The computer will record the growth. Note down the time that it started.3 Leave the plant by a window for three days. Make sure the plant has

enough water.4 The computer will show a graph of the growth of the seedling against

the time taken to grow.


5 Draw a sketch of the graph shown on the computer (or your teachermay give you a printout).

6 Label your graph with the time when you started the experiment.


1 When did the plant grow the quickest? Why do you think this is?2 When did the plant grow the slowest? Why do you think this is?

Evaluating

3 Think about how this experiment could be made better. Would each of thefollowing suggestions improve the experiment or not? Explain your answers.

� doing the experiment a few times� using more plants� carrying out the experiment for a shorter period of time� carrying out the experiment for a longer period of time

Do not eatthe seeds orplants.

Wash your handsafterwards.


C2bTeacher

activity notesLooking at leaves

Running the activityPupils work in pairs. The activity sheet gives a method for carrying out thepractical, and directs pupils to record a labelled diagram of the slide. Amicroscope could be linked to a video camera (e.g. Flexicam) to display slides tothe whole class.

Other relevant materialSkill sheet 1: Using a microscope

Expected outcomesPupils produce a labelled drawing of a section through the leaf as seen underthe microscope.

Safety notesPupils should take care with microscopes and slides. Microscopes using daylightillumination must never be used where direct sunlight may strike the mirror.Permanent damage to the retina may be caused by direct sunlight passingthrough the microscope into the eye.

ICT opportunitiesUse a Flexcam or QX3 digital microscope and projector to enlarge themicroscope image for discussion as a class.

Answers1 Palisade cells: contain the chloroplasts.

Chloroplasts: contain chlorophyll to trap light energy.

Air spaces: let gases go to and from stomata and spongy/palisade cells.

Stomata: let gases in and out of the leaf.

Waxy cuticle: prevents water being lost from the top surface of the leaf.

Vein: brings water from the roots, and takes glucose away to the rest ofthe plant.


Type Purpose DifferentiationPractical Pupils practise using a microscope and reinforce knowledge of the structure and

function of the leaf. Pupils look at pre-prepared leaf slides.Core


C2bTechnician

activity notesLooking at leaves


EquipmentFor the class:

� video camera, e.g. Flexicam (optional)� microscope

For each pair:

� pre-prepared (bought) slide of TS of a leaf, stained� microscope

For your informationRunning the activityPupils work in pairs. The activity sheet gives a method for carrying out thepractical, and directs pupils to record a labelled diagram of the slide. A microscopecould be linked to a video camera (e.g. Flexicam) to display slides to the whole class.

Expected outcomesPupils produce a labelled drawing of a section through the leaf as seen underthe microscope.

Safety notesPupils should take care with microscopes and slides. Microscopes using daylightillumination must never be used where direct sunlight may strike the mirror.Permanent damage to the retina may be caused by direct sunlight passing throughthe microscope into the eye.



function of the leaf. Pupils look at pre-prepared leaf slides.Core


C1aActivity

Core

Sheet 1 of 1

Sheet 1 of 1


ActivityCoreC2b Looking at leaves


C2b Looking at leaves

The leaf of a plant carries out photosynthesis. Each part of theleaf has a special function to help it carry out photosynthesis.You are going to look at a leaf under a microscope.

Obtaining evidence1 Put the slide on the microscope stage.2 Focus on your slide using the low power lens.3 Now look at the leaf using the high power lens.

Presenting the results4 Make a careful drawing in pencil to show what the

leaf looks like under the microscope.5 Label the parts of the leaf you can see.

Considering the evidence1 How does the structure of each part of the leaf help

the leaf to carry out photosynthesis?

The leaf of a plant carries out photosynthesis. Each part of theleaf has a special function to help it carry out photosynthesis.You are going to look at a leaf under a microscope.

Obtaining evidence1 Put the slide on the microscope stage.2 Focus on your slide using the low power lens.3 Now look at the leaf using the high power lens.

Presenting the results4 Make a careful drawing in pencil to show what the

leaf looks like under the microscope.5 Label the parts of the leaf you can see.

Considering the evidence1 How does the structure of each part of the leaf help

the leaf to carry out photosynthesis?

Take care withmicroscopesand slides.

Never use a microscopewhere direct sunlightmight get into it.




C3aTeacher

activity notesLooking at root hairs

Running the activityPupils work in pairs. The activity sheet gives a method for carrying out thepractical, and directs pupils to record a labelled diagram of the slide. Amicroscope could be linked to a video camera (e.g. Flexicam) to display slides tothe whole class.


Expected outcomesPupils produce a labelled drawing of a root as seen under the microscope.

Safety notesPupils should take care with microscopes and slides. Microscopes using daylightillumination must never be used where direct sunlight may strike the mirror.Permanent damage to the retina may be caused by direct sunlight passingthrough the microscope into the eye.

ICT opportunitiesUse a Flexicam or QX3 digital microscope and projector to enlarge themicroscope image for discussion as a class.

Answers1 Roots are branched and have root hairs to make sure they can absorb as

much water and nutrients as possible.

2 Holds the plant in the ground.



function of the root. Pupils look at pre-prepared slides of roots showing root hairs.Core


C3aTechnician

activity notesLooking at root hairs


EquipmentFor the class:

� video camera, e.g. Flexicam (optional)� microscope

For each pair:

� pre-prepared (bought) slide of TS or LS of a root, stained to show root hairs� microscope

For your informationRunning the activityPupils work in pairs. The activity sheet gives a method for carrying out thepractical, and directs pupils to record a labelled diagram of the slide. A microscopecould be linked to a video camera (e.g. Flexicam) to display slides to the whole class.

Expected outcomesPupils produce a labelled drawing of a root as seen under the microscope.

Safety notesPupils should take care with microscopes and slides. Microscopes using daylightillumination must never be used where direct sunlight may strike the mirror.Permanent damage to the retina may be caused by direct sunlight passing throughthe microscope into the eye.



function of the root. Pupils look at pre-prepared slides of roots showing root hairs.Core


C3aActivity

CoreLooking at root hairs

The roots of a plant absorb water and minerals for the plant.They do this through tiny root hairs. You are going to look ata root under a microscope.

Obtaining evidence

1 Put the slide on the microscope stage.2 Focus on your slide using the low power lens.3 Now look at the root using the high power lens and try to see

the root hairs.


4 Make a careful drawing in pencil to show what the root lookslike under the microscope. Make sure you include the structureof the root hair.

5 Label the parts you can see.


1 How does the structure of the root help the plant absorbwater and minerals from the soil?

2 What other function does the root have in the plant?





C3bTeacher

activity notesWater transport in celery


Pupils work in groups. They are instructed to leave celery stalks in dyed waterovernight and observe them the next day. To carry out the activity in the sameday, the celery stalks need to be left for at least a few hours before they are used.Alternatively, a cool hair dryer blowing over the leaves will speed up themovement of dye up the stalk.

The next day, pupils make a slide of a thin cross-section and observe it under amicroscope. Structured questions lead them to analyse the structure andfunction of the veins.

As a demonstration in parallel with this activity, a white carnation can be leftin dyed water overnight to show pupils that the dye travels up the veins andcolours the flower.


Expected outcomesThe celery stalk will become stained in the parts of the veins that carry water(xylem). With a very thin cross-section of the stalk, the structure of the stainedveins should become clearly visible under a light microscope.

PitfallsMake sure pupils cut very thin cross-sections. Some pupils may need helpwith this.

Safety notesPupils must use knives carefully. Take care with microscopes and slides.Microscopes using daylight illumination must never be used where directsunlight may strike the mirror. Permanent damage to the retina may be causedby direct sunlight passing through the microscope into the eye. Remind pupilsnot to eat the celery.

Answers1 All the way up to the leaves.

2 To transport water up the plant.

3 It is a long thin tube (or similar answer).


Type Purpose DifferentiationPractical Pupils observe coloured water travelling up the veins in a plant to reinforce knowledge

of the structure and function of veins in plants.Core


C3bTechnician

activity notesWater transport in celery


Equipment

For your informationRunning the activityNB: This activity needs to be run over two lessons.

Pupils work in groups. They are instructed to leave celery stalks in dyed water overnight andobserve them the next day. To carry out the activity in the same day, the celery stalks needto be left for at least a few hours before they are used. Alternatively, a cool hair dryerblowing over the leaves will speed up the movement of dye up the stalk.

The next day, pupils make a slide of a thin cross-section and observe it under a microscope.Structured questions lead them to analyse the structure and function of the veins.

As a demonstration in parallel with this activity, a white carnation can be left in dyed waterovernight to show pupils that the dye travels up the veins and colours the flower.

Expected outcomesThe celery stalk will become stained in the parts of the veins that carry water (xylem). Witha very thin cross-section of the stalk, the structure of the stained veins should becomeclearly visible under a light microscope.

PitfallsMake sure pupils cut very thin cross-sections. Some pupils may need help with this.

Safety notesPupils must use knives carefully. Take care with microscopes and slides. Microscopes usingdaylight illumination must never be used where direct sunlight may strike the mirror.Permanent damage to the retina may be caused by direct sunlight passing through themicroscope into the eye. Remind pupils not to eat the celery.


Type Purpose DifferentiationPractical Pupils observe coloured water travelling up the veins in a plant to reinforce knowledge

of the structure and function of veins in plants.Core

For the class (optional):

� hair dryer� white carnation� beaker� red food dye

For each group:

� celery stalk� beaker (a large one can be used to stand

all the celery stalks in for the class)� red food dye� craft knife or scalpel� white tile

� microscope slide� coverslip� mounted needle� distilled water� dropper� microscope


Water and minerals are taken up from the soil into the rootsof a plant. They are transported around the plant through theveins. You are going to look at these veins using a microscope.

Obtaining evidence

C3bActivity

CoreWater transport in celery


1 Stand some celery stalks in red dye. Leave them overnight.2 The next day, look at how far the dye has moved up the stalk.

Record your observations.3 Use a knife to cut a thin cross-section of dyed celery stalk.4 Place the section onto the slide. Put a few drops of distilled

water on the section. Carefully lower a coverslip over the slideas shown.


5 Draw a sketch of what you can see.


1 Look back at how far the dye moved up the stem. How far upthe plant do you think the veins go?

2 What is the function of the veins in the plant?3 Describe how the structure of the vein helps it to carry out its

function in the plant.

Take care withthe knife. It isvery sharp.

Take care withmicroscopes and slides.


Do not eat the celery.


C4aTeacher

activity notesProducts from biomass

Running the activityCore: Pupils should work independently. You could provide a range of referencesources for pupils in the classroom, or the research element may be carried out as ahomework activity.

Help: Pupils cut out and match statements and pictures from the activity sheet, tocomplete a description of how sugar cane is used in Brazil to produce fuel alcohol.

Other relevant materialSkill sheet 4: Web searches (for Extension)

Possible websites:

BeanfeastEuropaBio’s GM soya section

Golden syrupSilver Spoon website

Corn oil JD Hodges nutritional information

Vegetable protein Healthnotes foodnotes section

Cotton and paperConservation Online cellulose information

Paper and woodA brief history of paper making

Expected outcomesCore: Pupils make a table showing what they have found out about the differentproducts.

Help: Pupils make a poster or leaflet from their matched descriptions and pictures.

PitfallsEnsure pupils only use appropriate websites.

ICT opportunitiesExtension work could include searching the Internet for fuel alcohol productionfrom sugar cane. Pupils could try searching the key words biomass, fuel, sugarcane and Brazil. Pupils could produce a leaflet, poster or presentation of theirfindings.

AnswersCore: Beanfeast – proteins; cotton – cellulose; wooden furniture – cellulose;paper towels – cellulose; perfume – oils; corn oil – oils; sugar – sugars.

Help: The correct order is: Brazil is trying to save money... The sugar cane ischopped... The sugar cane is mixed...The fermented liquid is... The alcohol is...


Type Purpose DifferentiationICT Core pupils research which plant biomass substances are used to make different products.

Help pupils find out how alcohol for use as fuel is produced from sugar cane in Brazil. Thiscould also form the basis of an Extension activity (no sheet).

Core, Help


http://www.heinemann.co.uk/hotlinks/url.asp?urlid=9328






C4aActivity

CoreProducts from biomass

Many products we buy are parts of plants or have been madefrom plants. They may be produced from the proteins,cellulose, starch, oils and sugars that form part of the plants’biomass. You are going to do some research into plantproducts.

1 Look at this range of products.

2 Use the Internet and other resources to find out which substancesfrom the plants’ biomass are contained in each of these products.

3 Copy and complete this table.


Product Plant substance

Proteins Cellulose Starch Oils Sugars


C4aActivity

HelpProducts from biomass

In some parts of the world biomass is used to produce energy. Inthis activity you are going to find out how sugar cane is used inBrazil to produce alcohol for use as car fuel.

1 Cut out the pictures and the descriptions in the boxes below.2 Arrange them in the correct order.3 Use them to make a poster or a leaflet about fuel from biomass.


The sugar is mixed with yeast andleft to ferment. The yeast feeds onthe sugar, changing it to alcohol.

The alcohol is mixed with petrol andused by cars and lorries.

The sugar cane is chopped up andcrushed to squeeze out the juice.The juice is heated. The waterevaporates leaving sugar crystals.

Brazil is trying to save money byreducing oil imports. Sugar canecontains sugars made byphotosynthesis. They are changedinto alcohol that will burn, releasingenergy from the biomass.

The fermented liquid is distilled byheating it to 70 ºC. The vapour thatcomes off is then cooled. Itcondenses to form alcohol.


C4bTeacher

activity notesWhat fuel?

Running the activityPupils should work independently. You may have to work through an exampleon the board for pupils to understand the mathematics involved.

ICT opportunitiesIt would be possible to set up a spreadsheet for the results and subsequentcalculations.

Pupils could search the Internet for more information on how biomass is usedfor fuel.

Answers1 Honey 1329.4 kJ/g.

Wheat 1418.3 kJ/g.Rice 757.4 kJ/g.Cooking oil 3383.5 kJ/g.Couscous 1060.1 kJ/g.

2 no

3 Cooking oil.


Type Purpose DifferentiationPaper Pupils use information about the different nutrients in food to calculate the best food

to use as a fuel. The activity links the ideas of nutrients and biomass.Extension


C4bActivity

ExtensionWhat fuel?

We use petrol as a fuel for our cars. This is because petrol contains over 4500 kJ of energy in every 100 g! But what would happen if the petrol ran out, and we had to use plant biomass to make fuel? You are going to analyse different foods made from plants to see if any of them would provide as much energy per gram as petrol.

1 Look at the table.It tells you theenergy content ofthe main nutrientsin food.

2 Now look at the nutritional labels for honey, cooking oil, rice and couscous.They show you how many grams of each nutrient is in 100 g of food.

1 Calculate how much energy is provided by 100 g of each food.2 Do any of the foods provide more energy per 100 g than petrol?3 Which food would be the best replacement for petrol?


Carbohydrate Protein Fat

Glucose/Sucrose Cellulose Starch

17 kJ/g 17 kJ/g 17 kJ/g 17 kJ/g 37 kJ/g

honey wheat rice cooking oil couscous(g) (g) (g) (g) (g)

Glucose/Sucrose 78 1.3 0 0 1.5

Cellulose 0 3.0 0.2 0 2.8

Starch 0 66.2 40 0 37

Protein 0.2 10.1 3.7 0.1 8

Fat 0 1.3 0.3 91.4 6


C5aTeacher

activity notesDangers of deforestation

Running the activityPupils work in pairs to produce a campaign leaflet about deforestation. Theycould do this on paper or using desktop publishing software. Try to make themfocus on explaining the science as clearly as possible, on engaging the readerwith the issues, and on giving more than one person’s opinion on the issues.

Other relevant materialSkill sheet 4: Web searches

ICT opportunitiesPupils could search the Internet for more information about deforestationand the greenhouse effect. Useful websites could include Greenpeace andFriends of the Earth.

Pupils could produce their leaflets using desktop publishing software.


Type Purpose DifferentiationICT Pupils learn about the effects of deforestation on global climate by producing a

campaign leaflet.Extension




C5aActivity

ExtensionDangers of deforestation

People are cutting down forests all over the world. Thisdeforestation could have a catastrophic effect on carbondioxide levels in the atmosphere. You are going to design aleaflet to explain the dangers of deforestation.

1 Read the magazine article below. Look at any otherinformation you have from other sources about the dangersof deforestation.

2 You should decide which pieces of information would grabpeople’s attention and make them take notice. Use thisinformation on the front cover.

3 Inside the leaflet, you need to use science to explain whydeforestation is a problem. You should also mention whylogging is carried out by subsistence farmers and bycommercial companies.


The world’s forests aredisappearing. Four fifths of

them have been cut downbecause of mining, agricultureand commercial logging. TheAmazon rainforest is the size ofWestern Europe – an area of370 million hectares. Over thepast 30 years 15% of theBrazilian part of the forest hasbeen completely destroyed.This is equivalent to the area ofFrance!

About 2% of logs are cutdown by subsistence farmers.They’ve been cutting trees inthe same ‘small-scale’ waywithout any ill effects on theforest for hundreds of years. Butabout 80% of logging in theAmazon is done illegally. Even

the majority of commerciallogging authorised by somegovernments is very destructiveand is processed in a verywasteful way. On average, onlyone third of wood cut down inthe forest actually ends up inthe final product.

To understand whydeforestation is a problem, you need to understand thegreenhouse effect. Carbondioxide and other ‘greenhousegases’ act a little like the glassof a greenhouse and stop heatescaping from the Earth. Ifthere weren’t any greenhousegases in the atmosphere, itwould be about –5 °C all overthe world, and everywherewould be covered with ice.

So, it is important tomaintain a balance ofgreenhouse gases. The largeforests meant that it waspossible to keep increases incarbon dioxide (mainly fromvolcanic activity) in checkbecause trees convert carbondioxide into glucose andcellulose and release oxygenthrough photosynthesis. Now,only about half the world’sforests that existed a thousandyears ago remain, and muchmore greenhouse gases than inthe past are spewed into theatmosphere by burning fossilfuels. This has thrown thesystem out of balance, and theatmosphere is warming up. Weneed to stop deforestation now!

What’s happening in the Amazon?


C5bTeacher

activity notesMaintaining the balance

Running the activityPupils work in small groups to set up datalogging equipment over two lots of24 hours. It would be sensible to ask pupils to use the datalogging software toprepare and print the graphs immediately after finishing data collection.

Other relevant materialSkill sheet 27: Graphs with a spreadsheet

Expected outcomesPupils should produce graphs of carbon dioxide and oxygen levels over time,and they should answer the questions.

PitfallsThe pH and oxygen sensors can sometimes behave unpredictably. It isimportant to ensure they are calibrated in advance.

Be very gentle with both probes to avoid breaking them.

Safety notesWash your hands after handling the pond weed.

Answers1 carbon dioxide + water → glucose + oxygen (photosynthesis)

glucose + oxygen → carbon dioxide + water (respiration)

2 All the time.

3 During the day.

4 Pupils’ own responses.

5 Respiration was happening more quickly.

6 Pupils’ own responses.

7 Photosynthesis was happening more quickly.


Type Purpose DifferentiationICT Pupils use datalogging equipment to look at the interrelationship between

photosynthesis and respiration.Core


C5bTechnician

activity notesMaintaining the balance

Other relevant materialSkill sheet 27: Graphs with a spreadsheet

EquipmentFor each group:

� oxygen sensor� pH sensor� datalogging control box� computer� conical flask� split rubber bung for conical flask� pond weed

For the class:

� sodium hydrogen carbonate� spatula

For your informationRunning the activityPupils work in small groups to set up datalogging equipment over two lots of24 hours. It would be sensible to ask pupils to use the datalogging software toprepare and print the graphs immediately after finishing data collection.

Expected outcomesPupils should produce graphs of carbon dioxide and oxygen levels over time,and they should answer the questions.

PitfallsThe pH and oxygen sensors can sometimes behave unpredictably. It isimportant to ensure they are calibrated in advance.

Be very gentle with both probes to avoid breaking them.

Safety notesWash your hands after handling the pond weed.


Type Purpose DifferentiationICT Pupils use datalogging equipment to look at the interrelationship between

photosynthesis and respiration.Core


C5bActivity

CoreMaintaining the balance

To really see how respiration and photosynthesis fit together, you will study a plant over 24 hours and find out what gases it gives out. You will use a dataloggerbecause you can’t stay in school overnight. An oxygen probe will measure theamount of dissolved oxygen in the water. A pH probe will measure the pH of the water. The more carbon dioxide in the water, the more the pH goes down. This means we can use a pH probe to see how carbon dioxide levels change.

Equipment

� oxygen sensor � conical flask� pH sensor � split rubber bung for conical flask� datalogging control box � sodium hydrogen carbonate� computer � spatula� pond weed

Obtaining evidence

1 Set up the apparatus shown in the diagram.The way you do this will depend on yourdatalogging equipment.

2 Make sure the ends of the oxygen sensorand pH sensor are pushed between theleaves of the pond weed.

3 Allow the datalogger to run for 24 hours.4 Using your datalogging software, plot a

graph with time on the x-axis (going across) and oxygen on the y-axis (going up and down).

5 Repeat step 4, but for pH (carbon dioxide) instead of oxygen.


1 Write down the word equations for photosynthesis and respiration.

If photosynthesis and respiration happen at the same speed in the plant, then the levels of each gas in the water should stay constant.

2 When do plants respire?3 When do plants photosynthesise?4 At what time was the most carbon dioxide released into the water?5 At the same time, was photosynthesis happening more quickly than

respiration, or vice-versa?6 At what time was the most oxygen released into the water?7 At the same time, was respiration happening more quickly than

photosynthesis or vice-versa?


interface

oxygen sensor

pond weed

pH sensor

computer



C1 PlenariesHungry plants

Review learning� Pupils fill in a template ‘cooking recipe’ for photosynthesis

on the pupil sheet.

� Choose pupils to read out their recipe to the class.

Sharing responses� Pupils collate results and conclusions from Activity C1a or

C1b about photosynthesis.

� Conclude feedback by writing a word equation as a class.

Group feedback� In small groups, pupils discuss their answers to Activity

C1c.

� They should discuss why it may be a good idea to moveplants out of hospital wards at night.

Word game� In small groups, pupils prepare four questions about the

lesson’s content, for which they know the answers.

� Groups should swap sets of questions and try to answerthem.

Looking back� Set the question for pairs to consider and suggest answers

to. Then ask them to share their responses with otherpupils. Make it clear they may not know the answer andthey need to suggest their ideas and predictions.

� Pupils can summarise the suggestions and record them intheir books, to reconsider after further lessons.

➔ Pupil sheet

QuestionHow do plants get the reactants forphotosynthesis into their leaves?


Review learning

Pupils fill in a template‘cooking recipe’ forphotosynthesis.

Sharing responses

Collate results andconclusions from Activity C1aor C1b about photosynthesis.

Group feedback

In small groups, pupilsdiscuss answers fromActivity C1c.

Word games

In small groups, pupilsprepare four questions aboutthe lesson’s content to askanother group.

Looking ahead

In pairs, pupils suggest howplants get the reactants forphotosynthesis to their leaves.

C-Plenaries.qxd 17-Jun-04 8:40 PM Page 1

C1 PlenariesHungry plants

Review learning

Recipe for photosynthesis

Ingredients

Method




C2 PlenariesA food factory

Review learning� Pupils work in pairs and place all the cards face down. They take it in

turns to turn over two cards and look at them before returning themto face down. They need to remember where they are so that theycan turn up a leaf adaptation with how it helps the leaf tophotosynthesise together later. The person with the most correctpairs wins.

Sharing responses� As a class, ask pupils to share their ideas on what they think will

happen.

� Ask them to explain their predictions.

Group feedback� Pupils share ideas about the role of each part of the leaf from

Activity C2b.

� As a class, use a QX3 microscope and projector to relate pupils’feedback to the different parts of the leaf.

Word game� Initiate a word splat by asking pupils to devise questions that can be

answered by pointing at the key words for the lesson. The key wordsshould be written on the board/OHP.

� Divide the class into two groups and invite a pupil from each groupto stand close to the board/OHP.

� Choose a pupil to ask a question. The pupils by the board/OHP musteach say the word and try to point to it first. The loser choosesanother member of his or her group to stand by the board/OHP.

Looking ahead� Organise the class into groups of three.

� Give each pupil in the group one of the word pairs (see right). Askthem to think about what links/connects the two words.

� Pupils then discuss their ideas with other pupils who have also beengiven that word pair.

� Pupils return to their original group of three. Each group memberthen shares his information with their original group.

➔ Pupil sheet

Key wordspalisade cell, chlorophyll,chloroplasts, stomata, veinsRed only: specialised, diffuse

Word pairscarbon dioxide/leafnutrient/rootlight/leaf


Review learning

Pelmanism game matchingleaf parts to functions.

Sharing responses

Ask pupils to suggest whatwill happen in Activity C2a.

Group feedback

Pupils share ideas about the role ofeach part of the leaf from Activity C2b.

Word game

Word splat to checkprogress on leaf structures.

Looking ahead

Pupils discussword pairs.


C2 PlenariesA food factory

Review learning

Working with your partner, place all the cards face down.

Take it in turns to turn over two cards and look at them before turningthem face down again.

Remember where the cards are that you put back. You need to match upthe adaptation of a leaf, with how it helps the leaf to photosynthesise.

The person with the most correct pairs wins.


Catch a lot of light energy

Chlorophyll

Carries water from the roots to the leaves

Broad leaves

Cells pack in together tightly,catching a lot of light

Thin leavesStops water evaporating from the

top surface of the leaf

Long thin palisade cells

Lets light and gases reachthe centre of the leaf

Palisade cells at the top of the leaf


Stomata

Let gases in and out

Vein


Waxy layer



C3 PlenariesDon’t dry up!

Review learning� As a class, pupils describe the path of water through a plant

by completing a flowchart.� Start by drawing a box with ‘Water in the soil’ written in it.� Leave a space and in the last box, write ‘Water in the leaf

cells’.� Pupils should think of what to write in boxes in between

these two to complete the journey of water movementthrough a plant. Draw arrows to link the boxes in aflowchart.

Sharing responses� Collate results and conclusions from Activity C3b.� Focus on the movement of the ink and how that relates to

the slides.� Ensure pupils are clear about the functions of veins in

stems and leaves.

Group feedback� Pupils share ideas from Activity C3a about how root hairs

help the plant take in water and nutrients from the soil.� Ask pupils to use their ideas to design the pipework

connected to a pump for pumping water out of the soil.

Word game� Give each pupil a card containing a question and an

answer. Ask one pupil to stand up and read out just thequestion on their card, then sit down. The pupil who hasan appropriate answer to this question stands up, reads outtheir answer, then asks the question on their card and sitsdown, and so on.

� The game is complete when the pupil who started thegame stands up for a second time to read out the answeron their card. The loop is complete.

� If there are not enough question/answer cards for thewhole class, you may need to make extra copies. Somepupils will have the same question/answer card – the firstone to stand up gets to read their answer and ask theirquestion.

Looking ahead� As a class, pupils discuss why a carrot root is swollen with

stored food, rather than being branched and thin.� If possible, pass around a real carrot for pupils to look at.

➔ Pupil sheet

Equipmentcarrot


Review learning

As a class, draw a flowchartof water movement in aplant on the board.

Sharing responses

Collate results andconclusions fromActivity C3b.

Group feedback

Share ideas from Activity C3a abouthow root hairs help the plant take inwater and nutrients from the soil.

Word game

Loop game onphotosynthesis tocheck progress.

Looking ahead

As a class, discuss why a carrot rootis swollen with stored food, ratherthan being branched and thin.


C3 PlenariesDon’t dry up!

Word game


Q A

From where does a plant Taking in get its supply of glucose? water

Q A

What enters a plant Carbon through its roots? dioxide

Q A

What are root hairs for? To carryoutphoto-synthesis

Q A

How does water get from Water and the roots to the leaves? nutrients

Q A

What gas is produced by Photo-photosynthesis? synthesis

Q A

Why are leaves broad? Throughthe stem

Q A

Where do gases enter Oxygenand leave a plant?

Q A

Why do plants need To catchnutrients? as much

light aspossible

Q A

What gas is needed for Throughphotosynthesis? its leaves

Q A

What are chloroplasts for? To stayhealthy



C4 PlenariesUsing plant biomass

Review learning� Pupils play ‘What happens next?’ starting from

photosynthesis happening in a tree.

� Begin the story by saying that photosynthesis happens in atree and produces glucose.

� Ask pupils ‘What happens to the glucose?’

� For each answer they give, reply ‘What happens to it then?’or ‘What happens next?’

Sharing responses� Pupils share findings from activity C4a with the class, to

produce a table on the board of all the class results.

Group feedback� In groups, pupils share their calculations and conclusions

from Activity C4b.

� Emphasise that none of the foods provides as much energyas petrol, but that cooking oil and sugar cane haveadvantages for countries with no petrol supply and becausethey are renewable.

Word game� Pupils write a spider diagram to show how photosynthesis

relates to the production of biomass.

� Take suggestions from individuals to build up the spiderdiagram on the board.

Looking ahead� Give pupils the list of answers.

� Ask them to work in pairs to devise questions for each ofthese answers.

➔ Pupil sheet


Review learning

Play ‘What happensnext?’ starting fromphotosynthesishappening in a tree.

Sharing responses

Share findings from ActivityC4a to produce a table on theboard of all the group’s results.

Group feedback

In groups, pupils collateresults and conclusionsfrom Activity C4b.

Word game

Pupils write a spiderdiagram to show howphotosynthesis relates tothe production of biomass.

Looking ahead

Give pupils the list of answers. Askthem to work in pairs to devisequestions for each of theseanswers.


C4 PlenariesUsing plant biomass

Looking ahead

1 photosynthesis2 respiration3 carbon dioxide4 oxygen5 glucose

Sheet 1 of 1

Sheet 1 of 1


PlenariesC4 Using plant biomass

Looking ahead



Sheet 1 of 1

PlenariesC4 Using plant biomass

Looking ahead





C5 PlenariesSpot the difference

Review learning� Pupils reorganise statements about photosynthesis into

the correct order.

� Ask individuals to suggest their sequence and check theclass agrees with them.

Sharing responses� Pupils share results and conclusions from Activity C5b.

� Draw a sample graph of results on the board and askindividuals to label what is happening at various keypoints.

Group feedback� Pupils swap leaflets created from Activity C5a and

evaluate them against the criteria opposite. (Write thecriteria up on the board.)

Word game� Pupils complete a template mind map, showing how

photosynthesis and respiration are related.

� Use individual contributions to build up a class versionon the board.

Looking back� Pupils revise and consolidate knowledge from the unit.

They can use the Unit map, the Pupil checklist or theTest yourself questions.

➔ Pupil sheet

Answer1, 7, 5, 3, 4, 2, 6, 8

Criteria1 Does the front cover grab attention?

2 Are the reasons for deforestation clear?

3 Is the science of the greenhouse effectclearly explained?

4 Is there anything missing that youwould have included?

➔ Unit map

➔ Pupil checklist

➔ Test yourself


Review learning

Pupils reorganise statementsabout photosynthesis into thecorrect order.

Sharing responses

Collate results andconclusions from ActivityC5b.

Group feedback

Pupils swap leafletscreated from Activity C5aand evaluate them.

Word game

Complete a mind map, showinghow photosynthesis andrespiration are related.

Looking back

Pupils revise andconsolidate knowledgefrom the unit.


C5 PlenariesSpot the difference

Review learning

Reorganise these sentences into the order that they could happen:

Start here: 1 Water goes into the roots.

2 Glucose and oxygen react in respiration.

3 Carbon dioxide and water react in photosynthesis.

4 Glucose and oxygen are produced in photosynthesis.

5 Carbon dioxide goes into the leaves.

6 Carbon dioxide and water are produced in respiration.

7 Water travels up to the leaves.

Finish here: 8 Extra oxygen goes out of the leaves.



C1 SpecialsHungry plants

1 Look at this diagram of a ‘leaf factory’. It showshow a plant uses sunlight, water and carbondioxide to make its own food called glucose.

Use these words to label the diagram.

2 Use this word equation to help you complete the sentences.

energy from sunlightcarbon dioxide + water glucose (food) + oxygen

photosynthesis in leaves

a Plants make their own . They do this in their

.

b The food plants make is called .

c They make gas at the same time as they

make their food.

d To make food, plants use and .

The energy to make this happen comes from .

e The process of plants making their own food is called

.


.....................................

.........................................

.........................................

........................................................

........................................................

............................

.........................

....................................

oxygen

sunlight glucose light energy

water carbon dioxide

C-Specials.qxd 07-Jun-04 1:52 PM Page 1

C2 SpecialsA food factory

1 Look at this drawing of a leaf.

Use these words to label the drawing.

2 Cut out these jigsaw pieces.Join them together in pairs.Get them checked by your teacher.Stick them into your book.C


vein stomata waxy surface chloroplasts

Photosynthesis happens inthe ...

Leaves are broad and flatto ...

Leaves have holes calledstomata to ...

Leaves have a waxy surfaceto ...

... green chloroplasts.

... catch as muchsunlight as they can.

... let in carbon dioxideand let out oxygen.

... stop water being lost.Leaves have veins to ...

... transport water intothe leaf.


C3 SpecialsDon’t dry up!

1 Look at this drawing of a plant.

Use these words tolabel the drawing.

2 Draw lines to match the words to the descriptions.


root hairs

veins

nutrients

water

roots

Take in water and nutrients from thesoil. They hold the plant firm in the soil.

Make the surface of the roots bigger sothat they can take in water more quickly.

Needed for photosynthesis and to carry nutrients around the plant.

Carry water and nutrients all around the plant.

Help the plant to stay healthy.

root root hairs

stem

vein

leaf

3 A stick of celery was left in a red dye. Here isa drawing of a slice of the celery stem.

a Colour in where you’d see the red dye.

b The parts coloured red are:

leavesveinsroots

Tick the box toshow the right

answer.


C4 SpecialsUsing plant biomass

1 Use some of the words in this list to fill in the gaps.

a The total dry mass of plant material is called

.

b Photosynthesis makes .

c Some glucose is used to give the plant .

Some is used for .

d Glucose can be in the plant by

turning it into .

e Biomass can be burned to generate .

2 Write true or false for each sentence.

a Plants store glucose as starch to help them survive

into the next year.

b Plants cannot store starch in their roots.

c Plants store biomass in their seeds to help their

seedlings grow and develop.


energy starch

electricity growth biomass

glucosebioweight stored

magnetism


C4 SpecialsUsing plant biomass (continued)


GO

LDEN SYRU

PGolden syrup

Cane sugar syrup deliciouson pancakes and waffles

Textured vegetable protein

250 g

Packed on : Apr/04

Wooden furniture

Cotton shirt

From cotton plants and isused to make clothes.

From trees and is used forfurniture and building.

Protein from vegetables andoften eaten by vegetarians.

From corn plants, it containsfat. It is used for food.

From sugar cane and is usedto make foods like biscuits.

Corn oil

CORN OIL

100% PURE

3 Draw lines to match the pictures of biomass to their uses.


C5 SpecialsSpot the difference

1 Here are some sentences about plants.

Draw lines to match the beginnings and endings.

2 Look at this list of words.

a Use some of the words to fill in the gaps in this word equation forphotosynthesis.

chlorophyll+ carbon dioxide + oxygen

b Use some of the words to fill in the gaps in this word equation forrespiration.

glucose + + water + energy

3 Write true or false for each sentence.

a Plants make both carbon dioxide and oxygen gas.

b Plants do not respire.

c Animals make food by photosynthesis.


Respiration happens in ...

Photosynthesis happens in ...

Cutting down therainforests could make ...

Through the nightand day ...

... plants during the day.

... carbon dioxidelevels go up.

... both plants andanimals respire.

...every cell of everyanimal and plant.

glucoseoxygen

carbon dioxidesunlight water

heat


C Specials answersPlants and photosynthesis

C1 Hungry plants1 Clockwise from top right – oxygen, carbon

dioxide, water, light energy, glucose, sunlight.2 a food, leaves

b glucosec oxygend carbon dioxide, water, sunlighte photosynthesis

C2 A food factory1 Clockwise from top right – stomata, waxy

surface, chloroplasts, vein.2 Photosynthesis happens in the … green

chloroplasts.Leaves are broad and flat to … catch as muchsunlight as they can.Leaves have holes called stomata to … let incarbon dioxide and let out oxygen.Leaves have a waxy surface to … stop waterbeing lost.Leaves have veins to … transport water into theleaf.

C3 Don’t dry up!1 From the top – vein, stem, leaf, root, root hairs.2 water – Needed for photosynthesis and to carry

nutrients around the plant.roots – Take in water and nutrients from the soil.They hold the plant firm in the soil.root hairs – Make the surface of the roots biggerso that they can take in water more quickly.veins – Carry water and nutrients all around theplant.nutrients – Help the plant to stay healthy.

3 a Coloured in – the holes in the diagram.b veins

C4 Using plant biomass1 a biomass

b glucosec energy, growthd stored, starche electricity

2 a trueb falsec true

3 corn oil – From corn plants, it contains fat. It isused for food.golden syrup – From sugar cane and is used tomake foods like biscuits.TVP – Protein from vegetables and often eatenby vegetarians.wood – From trees and is used for furniture andbuilding.cotton – From cotton plants and is used to makeclothes.

C5 Spot the difference1 Respiration happens in … every cell of every

animal and plant.Photosynthesis happens in … plants duringthe day.Cutting down the rain forests could make …carbon dioxide levels go up.Through the night and day … both plants andanimals respire.

chlorophyll2 a water + carbon dioxide sunlight

glucose + oxygenb glucose + oxygen → carbon dioxide + water

+ energy3 a true

b falsec false


Spe Answers.qxd 6/23/2004 9:19 AM Page 3

C1 HomeworkHungry plants

HELP

1 The five statements below are about plants. Write down the letter for each statement and say whether it is true or false.

a Plants absorb everything they need from the soil.

b Plants take in oxygen for respiration all the time.

c Plants use heat energy from the Sun for photosynthesis.

d When plants photosynthesise they make sugars in their leaves.

e All green plants can photosynthesise.

2 Copy and complete the following sentences.

a Plants photosynthesise more during the summer because … .

b The reactants that plants use when they photosynthesise are … .

c Plants need the Sun for photosynthesis because … .

CORE

3 The diagram shows a plant growingunder glass. The rubber seal preventsmoisture and gases from entering orleaving the glass container.

a What gas in the container will notincrease during the night?

b What gas in the container willdecrease during the day?

c i When, in a 24 hour period, will the plant grow the most?

ii Explain your answer.

d Explain why it is necessary to have a watering tube outside the glass.

e i If the plant is continuously lit for a week, what will happen to the amount of carbon dioxide in the jar?

ii After two weeks of continuous lighting the plant stops photosynthesising.Explain why this happens in this experiment.

iii If plants do not photosynthesise their leaves lose their green colour. Explain why two weeks in the dark would produce pale yellow leaves.


rubber sheetwateringtube

plant growingthrough rubber seal

glass container

C-Homework.qxd 07-Jun-04 1:59 PM Page 1

C1 HomeworkHungry plants (continued)

EXTENSION

4 Aimee is trying to find out if all types of light are suitable forphotosynthesis. She is using pondweed and counting thenumber of bubbles it makes per minute with differentlycoloured lights. Her results are shown below.

a Which colour of light is most strongly absorbed duringphotosynthesis?

b With which colour is photosynthesis slowest?

c What gas is in the bubbles coming from the pondweed?

d i Explain how you can tell that white light helpsphotosynthesis.

ii Explain why photosynthesis is slower in white light thanin red or blue light.

e Write down the symbol equation for photosynthesis.


Colour of light Number of bubbles per minute

White 38

Red 67

Blue 80

Green 6


C2 HomeworkA food factory

HELP

1 The diagram shows the cells in across-section from a leaf.

a What is the name of the structurelabelled E?

b What type of cell is in layer B?

c What is the function (job) ofpart C?

d i A is a waxy layer. What does it do?

ii Explain why this is important.

e Why is structure D green?

f Copy and complete the followingsentences.

i Most leaves are wide and flat because … .

ii Chloroplasts are mostly in the upper surface of a leaf because … .

CORE

2 Look again at the diagram for question 1.

a Explain how the shape and position of the cells in layer B helpsphotosynthesis.

b Other than the shape and position, how can you tell that these cellsare where most photosynthesis takes place?

c i Which gas enters the leaf through point C?

ii Which gas leaves through the same point?

d Explain how the water needed for photosynthesis reaches the leaves.

e Conifers have very narrow leaves, which they keep all year round.Broad-leaved trees develop leaves in spring and lose their leaves inthe autumn. Describe how this affects how broad-leaved trees andconifers photosynthesise.


C

E

D

Layer B

A


C2 HomeworkA food factory (continued)

EXTENSION

3 a Explain why green plants photosynthesise.

b Fungi are usually white or pale brown. They live on rotting treetrunks or rotting vegetation in the soil.

i Explain why fungi do not photosynthesise.

ii Suggest why fungi only grow on rotting vegetation.

4 The graph shows the light levels in Gary’s greenhouse during aday in March.

a How many hours of growing time do the plants in Gary’s greenhousehave, on the day shown?

b What might have caused the dips in light levels around 11 am and 3 pm?

c At what time will photosynthesis be fastest?

d What will be happening to the rate of photosynthesis between 2 pmand 3 pm?

e Suggest one way in which Gary could increase the number ofgrowing hours for his plants.


1 2 3 4 5 6 7 8 9 10 11 midday

1 2 3 4 5 6 7 8 9 10 11midnight

0

1

2

3

4

Time of day

Lightlevel

inlux


C3 HomeworkDon’t dry up!

HELP

1 The diagrams show Carly’s plant. Carly has been ill and spent a week in bed, just after she bought the plant from the florist.

a Copy and complete the sentences below.

i After one week the soil in Carly’s plant pot had … .

ii We know that Carly watered her plant on the seventh day because … .

iii To keep her plant from drooping again Carly must … .

iv Carly should add fertiliser to the plant pot because … .

v When Carly pulls on the stem of the plant it comes out of the pot withall the soil attached because … .

b i What process uses the water that Carly adds to the soil?

ii Where in the plant does this process happen?

iii How does the water get from the roots to this place?


Plant onday 1

Plant after7 days

Plant after8 days


C3 HomeworkDon’t dry up! (continued)

CORE

2 Dandelions have a single ‘tap’ root that goes down a very long way into the soil. Couch grass has a mass of fineroots that spread out just under the surface of the soil.

a i What is the disadvantage of asingle tap root?

ii What is the advantage of a root that goes a long way down into the soil?

b i What is the advantage of having a mass of spreading roots?

ii What is the disadvantage of roots that are all close to the soil surface?

c Both types of roots have tiny root hairs.

i Describe what a root hair cell is like.

ii Explain how root hair cells improve the uptake of water by the plant.

d i What important substances, other than water, are also absorbed by roots?

ii Explain how the roots are able to absorb these substances.

EXTENSION

3 The diagram shows a white rose that has beenspecially treated by the grower. Normal white roses do not have coloured tips to their petals.After it was cut for sale, the rose was placed into a container of blue dye for a while. Then it wastaken out and put back into fresh water.

a i Explain how the blue colour has reachedthe tips of the petals.

ii Why is the blue colour only in the tips of each petal and not all over the whole of each petal?

iii What should the grower do if she wants the petals to have red tips instead of blue tips?

b The petals in the rose need sugars but cannot make it.

i Why can’t the petals make sugars?

ii How do sugars get to the petals?

c Give a reason why all cells need water, other than for photosynthesis.


white petals

blue tips

dandelion couch grass


C4 HomeworkUsing plant biomass

HELP

1 Leroy is doing an experiment to find the energy provided by burningtwo sorts of biomass.

a Give three things that Leroy must do to make sure that hisexperiments are fair.

b Give two things that Leroy must do to make sure that hisexperiments are safe.

c Here is Leroy’s results table.


thermometer

clamps

water

burningbiomass

crucible

Leroy's apparatus

Type of biomass Water temperature Water temperature at start in °C after burning in °C

Sunflower seeds 16 48

Straw 18 37

i Which type of biomass provided the most energy?

ii Explain how you can tell.

d Leroy looked up the amounts of energy from his two types ofbiomass on the Internet. His experiments gave smaller amounts ofenergy than the website figures. Suggest why Leroy’s results were too low.


C4 HomeworkUsing plant biomass (continued)

CORE

2 Power stations burn both biomass and fossil fuels to generate electricity.

a What type of energy is stored in both biomass and fossil fuels?

b Biomass is often described as a renewable energy resource. Explainwhat is meant by ‘renewable energy resource’.

c Give one advantage of using biomass instead of fossil fuels.

d What are the products when both types of fuel are burnt?

e Explain why using these fuels is bad for the environment.

3 a Photosynthesis produces glucose. Name two ways that plants use the glucose.

b Some plants store the glucose in their roots. In what form is it stored?

c Explain why they store some of the glucose in this way.

EXTENSION

4 a In many plants, much of the glucose from photosynthesis isconverted to cellulose. Give one useful product that consists of cellulose.

b Explain why cellulose is important to plants.

5 Sandy did an experiment to find out whatsubstances form the biomass of a geraniumleaf. The leaf she chose was green in thecentre and white around the edges. Thediagram shows her leaf.

Sandy boiled her leaf in alcohol to removethe green colouring.

a What substance should Sandy now putonto the leaf to find out if it containedstarch?

b Describe what the leaf would look like after Sandy put this substance onto the leaf.

c Explain why the leaf gave these results.

d How would Sandy’s results have been different if the geranium had been in the dark for several days, before she tested the leaf?


Sandy's leaf

white edge

(green) centre


C5 HomeworkSpot the difference

HELP

1 a i Match the beginning of each sentence with the correct ending. Write out the complete sentences.


Beginnings Endings

A Carbon dioxide and water 1 only when it is light.react during photosynthesis

B Plants respire 2 to make carbon dioxide and water.

C Plants photosynthesise 3 during the night.

D During respiration the products 4 plants break down their sugars to of photosynthesis react get energy.

E Carbon dioxide is released from 5 all the time.plants through the stomata

F During respiration 6 to make glucose and oxygen.

ii What are the two other things that plants need when they photosynthesise?

b Write down the word equation for respiration.

CORE

2 The graph shows the levels of carbon dioxide and oxygen in Mrs Green’s bedroom over a 24 hour period in December. She likes to have lots of houseplants in her bedroom. She keeps her windows closed during the winter.

midnightmidday0

5

10

15

20

25

A

B

% o

f gas

in t

he a

ir


C5 HomeworkSpot the difference (continued)

a i Which line shows the level of carbon dioxide?

ii Both Mrs Green and her houseplants are responsible for the levelof carbon dioxide. Explain why the carbon dioxide graph has theshape shown.

iii How would the carbon dioxide graph be different if Mrs Greenhad no houseplants in her room?

iv How will the carbon dioxide graph be different when Mrs Greenis on a winter holiday?

b The level of oxygen during the day in Mrs Green’s bedroom is higherthan in most bedrooms in December. Explain why it is higher.

c Mrs Green’s neighbour says that Mrs Green should open a bedroomwindow every night. Explain why this is a good idea.

EXTENSION

3 a i Write down the symbol equation for photosynthesis.

ii How is the equation for respiration related to the one you havejust written for photosynthesis?

b Explain why photosynthesis is vital for animals to survive.

c Describe how an atom of carbon, that was once part of a dinosaur,could end up on your plate in a sausage.



C1Homework

mark schemeHungry plants


HELPQuestion Answer Mark

1 A – False; B – False; C – False; D – True; E – True. 51 mark for each correct response.

2 a Underscores are pupil response. Accept equivalent responses.Photosynthesis happens better during the summer because there ismore sunlight. 1

b The reactants that plants use when they do photosynthesis are carbon dioxide and water 1

c Plants need the Sun because they need light energy to do photosynthesis 1

Total for Help 8

COREQuestion Answer Mark

3 a Oxygen 1

b Carbon dioxide 1

c i When it is light/during the day. 1

ii Plants need light for photosynthesis. 1

d Plants need water from the soil for photosynthesis. 1

e i It will decrease to nothing/there will be none left. 1

ii There is no carbon dioxide left in the container and 1no more can get in because of the rubber seal, 1so the plant cannot photosynthesise any more. 1

iii There would be no light for photosynthesisso the green colour would be lost from the leaves. 1

Total for Core 10

EXTENSIONQuestion Answer Mark

4 a Blue 1

b Green 1

c Oxygen 1

d i There is a reasonable number of bubbles/bubbles are beingproduced/oxygen is being produced. 1

ii White light contains all the colours of the spectrum 1so the amount of blue and red light is less than with the pure colours. 1

e 6CO2 + 6H2O C6H12O6 + 6O2 2Award one mark for correct formulae and one for balancing.

Total for Extension 8


C2Homework

mark schemeA food factory



1 a Nucleus 1

b Palisade cell. 1

c To let air/gases/carbon dioxide into the leaf or to let oxygen out of the leaf. 1

d i Stops the leaf from drying out. 1

ii Water is needed for photosynthesis. 1

e It contains chlorophyll. 1

f i Most leaves are wide and flat because this lets them absorb lots of light. 1Underscore is pupil response. Accept equivalent responses.

ii Chloroplasts are mostly in the upper surface of a leaf because theycan get the most sunlight there for photosynthesis. Underscore is 1pupil response. Accept equivalent responses.

Total for Help 8


2 a Pack closer together so absorb more light; at the top ofthe leaf so nearest to the Sun. 2

b They have the most chloroplasts. 1

c i Air/carbon dioxide. 1

ii Oxygen 1

d From roots in the soil 1through the veins. 1

e Broad-leaved plants photosynthesise a lot in spring and summer. 1Narrow-leaved plants cannot photosynthesise as much in spring and summer 1so they have to be able to photosynthesise all year round. 1Accept equivalent alternative responses.

Total for Core 10


3 a To make the food they need for life processes. 1

b i They have no chlorophyll/chloroplasts. 1

ii They get their food directly from other vegetation. 1

4 a 12 hours. 1

b Clouds/it was raining. Accept other sensible suggestions. 1

c 1 pm. 1

d It will be getting slower/falling. 1

e Use artificial light. 1



C3Homework

mark schemeDon’t dry up!



1 a Accept equivalent responses for parts i – v.

i After one week the soil in Carly’s plant pot had dried out. 1

ii We know that Carly watered her plant on the seventh day becausethe plant stopped being droopy. 1

iii To keep her plant from drooping again Carly must water it regularly. 1

iv Carly should add fertiliser to the plant pot because it containsnutrients the plant needs. 1

v When Carly pulls on the stem of the plant it comes out of the potwith all the soil attached because the roots fix it into the soil. 1

b i Photosynthesis. 1

ii In the leaves/green parts of the plant. 1

iii Through the veins. 1

Total for Help 8


2 Accept equivalent responses for parts a i to b ii.

a i It only touches a small part of the soil surface 1so cannot get water from far away from the plant. 1

ii It can reach down for water when the surface has dried out. 1

b i They can gather water over a wide area. 1

ii They dry out quickly when there is no rain. 1

c i The cells have long thin parts. 1

ii The root hair increases the surface area 1and there are lots of root hairs. 1

d i Nutrients 1

ii The nutrients are soluble in water. 1

Total for Core 10


3 a i It has been absorbed into the stem 1and travelled to the petals through veins. 1

ii The rose was only in the dye for a short time 1and then water was absorbed into the stems again. 1

iii Stand the cut flower in red dye. 1

b i They have no chlorophyll/cannot photosynthesise. 1

ii Through veins dissolved in water. 1

c To keep their shape/to stay rigid. 1



C4Homework

mark schemeUsing plant biomass



1 a Any three from: same volume of water; same mass of biomass burnt;water starts at the same temperature; flame same distance from boilingtube; protect from draughts. 3

b Any two from: point the tube away from people; the tube is clamped;the apparatus is away from the edge of the bench; the tube is over thebase of the stand. Do not accept references to personal protection, such as 2eye protection or tied-back hair etc.

c i Sunflower seeds. 1

ii Higher temperature change (32 °C). 1

d One appropriate point from: not all the heat went into the water; thefuel did not burn properly; some of the heat went into the glass boiling tube. 1

Total for Help 8


2 a Chemical energy. 1

b They can be easily replaced/more can be produced. 1Do not accept references to re-use.

c Will not run out/can grow some more quickly. 1

d Carbon dioxide and water. 1

e Carbon dioxide is a pollutant 1responsible for global warming/involved in the greenhouse effect. 1

3 a As the fuel for respiration. 1To make new plant cells/to grow. 1

b Starch 1

c So they can use it as their food source later. 1

Total for Core 10


4 a Wood/cotton. Accept other suitable responses. 1

b It forms their cell walls/provides strength/provides support. 1

5 a Iodine solution. Response must refer to solution. 1

b The edges would be yellow/would not be blue-black/would not change. 1The centre part would be blue-black. 1

c Photosynthesis needs chlorophyll. 1There was chlorophyll in the centre part of the leaf but not in the edges. 1

d None of the leaf would turn blue-black with iodine solution. 1



C5Homework

mark schemeSpot the difference



1 a i Correct matches are: A – 6; B – 5; C – 1; D – 2; E – 3; F – 4. 55 or 6 correct = 5 marks; 4 correct = 4 marks etc.

ii Chlorophyll and sunlight. 2

b sugar/glucose + oxygen carbon dioxide + water 1

Total for Help 8


2 a i Line A. 1

ii Both are respiring at night 1which produces carbon dioxide; 1but no photosynthesis is happening at night. 1

iii It would still be higher at night but not so high. 1

iv It will be much lower. 1

b All the plants are photosynthesising 1which gives off oxygen. 1

c It would allow fresh air in to replace the oxygen used up during respiration 1and it would enable some of the carbon dioxide to escape. 1

Total for Core 10


3 a i 6CO2 + 6H2O C6H12O6 + 6O2Award 1 mark for correct formulae and 1 mark for balancing. 2

ii It is the same thing in reverse. 1

b Animals need glucose for respiration 1but they cannot make it by photosynthesis 1so they eat plants that photosynthesise. 1

c The dinosaur breathed out carbon dioxide into the air. 1Carbon dioxide from the air goes into the plant that is inthe sausage/eaten by the pig that went into the sausage. 1



C Test yourselfPlants and photosynthesis

1 Complete these sentences by crossing out the words that are wrong.

a Plants do/do not take in soil from the ground as they grow.

b During photosynthesis plants take in water through their leaves/roots.

c Plants also take in carbon dioxide/oxygen to make glucose.

2 Complete the following word equation for photosynthesis.

+ water → + oxygen

3 The following steps were carried out by a student who was doing an experiment to see if light is needed for photosynthesis. The steps are in the wrong order. Write a number next to each step to show its correct order.

Boil the leaf in hot alcohol. Place the leaf in boiling water.

Cover part of leaf with black paper. Remove the black paper.

Add iodine solution to the leaf. Make a note of whether the

Leave the leaf in the light for 24 hours.iodine turns black.

4 Draw lines to match each process with the correct reason for doing it.

Process Reason

boil the leaf in water � � turns black if starch is present

boil the leaf in alcohol � � breaks down the cell walls

add iodine solution � � dissolves out the chlorophyll

5 Complete the sentences below. Choose from these words to fill in the gaps. You may use each word once, more than once, or not at all.

As the amount of light increases, the rate of photosynthesis .

The rate of photosynthesis in some water plants can be determined by

counting the number of bubbles given off.

Plants use a green pigment called to carry out the process of photosynthesis.

Most photosynthesis takes place in the cells in the

part of the leaf, because they receive more .


chlorophyll increases light oxygen upper

Test-Qust.qxd 6/25/2004 10:32 AM Page 8

C Test yourselfPlants and photosynthesis (continued)

6 Put a tick against the following substances if you think they are made from biomass of plants.

plastic rubber

wood nylon

cotton starch

7 The diagram shows the different parts of a plant. However, the labels are missing.

Complete the label boxes by copying out the correct descriptions from the boxes below.


branching and a large surface area for taking

in water

cells through which water is absorbed and nutrients pass into the

plant

air spaces containing oxygen that the roots need for respiration

glucose (the source of all biomass in the

plant) made here by photosynthesis using water from the roots and carbon dioxide

from the air

carries water up the plant to the leaves for

photosynthesis


C Test yourselfPlants and photosynthesis (continued)

8 Complete the sentences below to describe the effects of plants on the environment. Choose from these words to fill in the gaps. You may use each word once, more than once, or not at all.

Photosynthesis and respiration together ensure that the level of

carbon dioxide in the atmosphere is .

However, because modern societies burn a lot of fuels, the level of

carbon dioxide is .

Cutting down and burning rainforest is also responsible for

levels of carbon dioxide. Only by reducing

the amount of fuel that we burn and conserving the rainforests

can we ensure levels of carbon dioxide.

Plants release energy from food by .

Humans and animals rely on to use carbon dioxide and produce oxygen for them to respire.

9 The graph shows both the rate of respiration and the rate of photosynthesis in a flowering plant.

a During what period of time is photosynthesis faster than respiration?

b At which two times does the rate of photosynthesis equal the rate

of respiration?


respiration constant rising falling plantsRa

te o

f rea

ctio

n

midnight

Time of day

4 a.m. 8 a.m. midday 4 p.m. 8 p.m. midnight

respiration

photosynthesis


CTest yourself

AnswersPlants and photosynthesis

1 Complete these sentences by crossing out the words that are wrong.

a Plants do/do not take in soil from the ground as they grow.

b During photosynthesis plants take in water through their leaves/roots.

c Plants also take in carbon dioxide/oxygen to make glucose.

2 Complete the following word equation for photosynthesis.

+ water → + oxygen

3 The following steps were carried out by a student who was doing an experiment to see if light is needed for photosynthesis. The steps are in the wrong order. Write a number next to each step to show its correct order.

Boil the leaf in hot alcohol. Place the leaf in boiling water.

Cover part of leaf with black paper. Remove the black paper.

Add iodine solution to the leaf. Make a note of whether the

Leave the leaf in the light for 24 hours.iodine turns black.

4 Draw lines to match each process with the correct reason for doing it.

Process Reason

boil the leaf in water � � turns black if starch is present

boil the leaf in alcohol � � breaks down the cell walls

add iodine solution � � dissolves out the chlorophyll

5 Complete the sentences below. Choose from these words to fill in the gaps. You may use each word once, more than once, or not at all.

As the amount of light increases, the rate of photosynthesis .

The rate of photosynthesis in some water plants can be determined by

counting the number of bubbles given off.

Plants use a green pigment called to carry out the process of photosynthesis.

Most photosynthesis takes place in the cells in the

part of the leaf, because they receive more .light

upper

chlorophyll

oxygen

increases

2

76

31

45

dioxideglucose

carbon


chlorophyll increases light oxygen upper

Test-Ans.qxd 16-Jun-04 2:54 PM Page 8

CTest yourself

AnswersPlants and photosynthesis (continued)

6 Put a tick against the following substances if you think they are made from biomass of plants.

plastic rubber

wood nylon

cotton starch

7 The diagram shows the different parts of a plant. However, the labels are missing.

Complete the label boxes by copying out the correct descriptions from the boxes below.

��

�

�


air spaces containing oxygen that the roots need for

respiration

glucose (the source of all biomass in the plant) made here by photosynthesis using

water from the roots and carbon

dioxide from the air

carries water up the plant to the leaves for photosynthesis

branching and a large surface area

for taking in water

cells through which water is absorbed and nutrients pass

into the plant


CTest yourself

AnswersPlants and photosynthesis (continued)

8 Complete the sentences below to describe the effects of plants on the environment. Choose from these words to fill in the gaps. You may use each word once, more than once, or not at all.

Photosynthesis and respiration together ensure that the level of

carbon dioxide in the atmosphere is .

However, because modern societies burn a lot of fuels, the level of

carbon dioxide is .

Cutting down and burning rainforest is also responsible for

levels of carbon dioxide. Only by reducing

the amount of fuel that we burn and conserving the rainforests

can we ensure levels of carbon dioxide.

Plants release energy from food by .

Humans and animals rely on to use carbon dioxide and produce oxygen for them to respire.

9 The graph shows both the rate of respiration and the rate of photosynthesis in a flowering plant.

a During what period of time is photosynthesis faster than respiration?

b At which two times does the rate of photosynthesis equal the rate

of respiration? At 10 a.m. and 6 p.m.

Between 10 a.m. and 6 p.m.

plants

respiration

constant

rising

rising

constant


respiration constant rising falling plantsRa

te o

f rea

ctio

n

midnight

Time of day

4 a.m. 8 a.m. midday 4 p.m. 8 p.m. midnight

respiration

photosynthesis


CEnd of unit test

GreenPlants and photosynthesis

1 Write out two things from the following list that a plant uses to make food.

• starch • glucose• water • light• oxygen 2 marks

2 Look at the list below. From where does a plant obtain:

a carbon dioxide? b water? 2 marks

3 In which part of the plant does each of the following processes take place?

a absorption of water b photosynthesis 2 marks

4 Rita’s class was asked to write down the word equation for photosynthesis.

Four of the different answers produced by the class are listed below.

A oxygen + glucose → carbon dioxide + waterB oxygen + water → carbon dioxide + glucoseC carbon dioxide + water → glucose + oxygenD oxygen + carbon dioxide → water + glucose

a Which was the correct equation for photosynthesis? 1 mark

b Which was the correct equation for respiration? 1 mark

5 Peter examined the leaves of a plant he had grown.He noticed the leaf had various features.Explain how each of the features below enables leaves to carry out their function.

a a large surface area b green 2 marks

6 When the plant had grown, Peter carefully removed it from the soil.He looked at the root structure and noticed several features.

a Explain how each of the features below enables roots to absorb water. 3 marks

i a branching structureii a large deep rootiii many tiny, long thin root hairs

b Why do plants need to take up nitrates through their roots? 1 mark


air fertiliser minerals soil water vapour

A-C-EUTest.qxd 07-Jun-04 4:40 PM Page 17

CEnd of unit test

GreenPlants and photosynthesis (continued)

7 Plants produce biomass. Biomass can be useful to us in many different ways. One example is sugar from sugar cane.

a Name one other use of biomass. 1 mark

b What is the name of the process by which a plant produces biomass? 1 mark

8 Respiration is the process in which living things break down molecules of glucose to release energy.

a Four different statements about the difference between photosynthesis and respiration are given below. Which two are correct? 2 marks

A Photosynthesis uses light energy, respiration releases energy.B Photosynthesis uses water and oxygen, respiration releases water and oxygen.C Photosynthesis does not need chlorophyll, respiration needs chlorophyll.D Photosynthesis produces glucose, respiration uses glucose.

b State the source of the energy for the process of photosynthesis. 1 mark

c Describe how you would test a sample of biomass to show the presence of starch. 1 mark

9 Katie has set up this experiment:

She has put hydrogencarbonate indicator into each test tube. This indicator changescolour when the amount of carbon dioxide in the test tube changes. The colourchanges of the indicator are shown in this table:


Colour of indicator solution Amount of dissolved carbon dioxide

reddish orange same as in the air

purple less than in the air

yellow more than in the air

A B Ccontains

waterweedcontains

small snailscontains

small snailsand

waterweed


CEnd of unit test

GreenPlants and photosynthesis (continued)

a What factor (dependent variable) is being observed in the investigation? 1 mark

b i David says that Katie should have a fourth test tube with no organisms in it. Why would it be important to have this fourth tube? 1 mark

ii What should Katie put in the fourth test tube to make the experiment fair? 1 mark

Katie left the test tubes in sunlight for two hours. These are her results:

c i David said that 10 minutes should be long enough, but Katie said he was wrong. Why did she say this? 1 mark

ii Katie says that the results of test tube B show that plants always use upcarbon dioxide. Is this a fair conclusion to make? Give a reason. 1 mark


Test tube A B C

Colour yellow purple reddish orange


CEnd of unit test

RedPlants and photosynthesis

1 Peter examined the leaves of a plant he had grown. He noticed the leaf had various features.

Explain how each of the features below enables leaves to carry out their function.

a large surface area 1 mark

b green 1 mark

2 When the plant had grown, Peter carefully removed it from the soil.

He looked at the root structure and noticed several features.

a Explain how each of the features below enables roots to carry out their function. 2 marks

i a branching structureii tiny root hairs

b Why do plants need to take up nitrates through their roots? 1 mark

3 Rita’s class was asked to write down the word equation for photosynthesis.

Four of the different answers produced by the class are listed below.

A oxygen + glucose → carbon dioxide + waterB oxygen + water → carbon dioxide + glucoseC carbon dioxide + water → glucose + oxygenD oxygen + carbon dioxide → water + glucose

a Which was the correct equation for photosynthesis? 1 mark

b Which was the correct equation for respiration? 1 mark

c Raymond did an experiment to measure what two substances were absorbed by a plant in order to photosynthesise. To explain what happens in photosynthesis, he decided to write a symbol equation. He wrote down some of the chemical formulae, but failed to complete the equation.

Copy and complete Raymond’s equation: 2 marks

+ 6CO2 → C6H12O6 +



CEnd of unit test

RedPlants and photosynthesis (continued)

4 Plants produce biomass. Biomass can be useful to us in many different ways. One example is sugar from sugar cane.

a Name one other use of biomass. 1 mark

b What is the name of the process by which a plant produces biomass? 1 mark

5 Respiration is the process in which living things break down complex molecules such as starch to release energy.

a Describe two ways in which this process differs from photosynthesis. 2 marks

b State the source of the energy for the process of photosynthesis. 1 mark

c Describe how you would test a sample of biomass to show the presence of starch. 1 mark

6 a Plant cells in the root are adapted to absorb water from their immediatesurroundings.

Explain how having a long thin hair-like shape helps a root to absorb water. 1 mark

b Palisade cells in the leaf are adapted for photosynthesis.

Describe two features that help a palisade cell to photosynthesise. 2 marks

7 Plants require carbon dioxide for photosynthesis and produce oxygen as a waste product. The carbon dioxide diffuses into the leaf through small holes on the under surface and oxygen diffuses out.

Explain what effect you think the following changes would have on the rate at which photosynthesis takes place:

a an increase in the level of atmospheric carbon dioxide 1 mark

b a decrease in the amount of chlorophyll in the leaf cells. 1 mark


upperepidermis

lowerepidermis

chloroplast

palisademesophylllayer

spongymesophylllayer

stoma

xylem invascularbundle(vein)

cuticle


CEnd of unit test

RedPlants and photosynthesis (continued)

8 Katie has set up this experiment:

She has put hydrogencarbonate indicator into each test tube. This indicator changes colour when the amount of carbon dioxide in the test tube changes. The colour changes of the indicator are shown in this table:

Katie left the test tubes in sunlight for two hours. These are her results:

a David said that 10 minutes should be long enough, but Katie said he was wrong. Why did she say this? 1 mark

b Katie says that the results of test tube B shows that plants always use up carbon dioxide. Is this a fair conclusion to make? Give a reason. 1 mark

c Katie has another test tube, identical to B. What could she do with it to check her conclusion? 1 mark

d How could Katie improve the reliability of her results in her experiment? Give two ways. 2 marks


Test tube A B C

Colour yellow purple reddish orange

Colour of indicator solution Amount of dissolved carbon dioxide

reddish orange same as in the air

purple less than in the air

yellow more than in the air

A B Ccontains

waterweedcontains

small snailscontains

small snailsand

waterweed


CEnd of unit test

mark schemePlants and photosynthesis


Green (NC Tier 3–6)Question Answer Mark Level

1 Water 1 3Light 1 3

2 a Air 1 4

b Soil 1 4

3 a Roots 1 4

b Leaves 1 4

4 a C or carbon dioxide + water → glucose + oxygen 1 6

b A or oxygen + glucose → carbon dioxide + water 1 6

5 a Can absorb more carbon dioxide or light or get rid of more oxygen. 1 5

b Contains chlorophyll to trap energy from sunlight or contains chlorophyll for photosynthesis. 1 5

6 a i To reach many parts of the soil. 1 5ii To get to water deep down or to reach the water table. 1 5iii Give a large surface area for absorption. 1 5

b To grow or make proteins. 1 5

7 a Any suitable example, e.g. wood for burning. 1 5

b Photosynthesis 1 6

8 a A and D. 1, 1 6

b Light or sunlight or the Sun. 1 5

c Add iodine solution – the starch in biomass turns black. 1 5

9 a Amount of carbon dioxide. 1 4

b i Make sure it was the organisms, not some other factor, causing the effect. 1 5

ii Same amount of liquid/indicator as other tubes. 1 5

c i Need to leave enough time for the experiment to stabilise/snails and plants respire slowly. 1 6

ii No, she has only tested it in the light. 1 6

Scores in the range of: NC Level

3–6 3

7–11 4

12–16 5

17–25 6


CEnd of unit test

mark schemePlants and photosynthesis


Red (NC Tier 5–7*)Question Answer Mark Level

1 a Can absorb more carbon dioxide or light or get rid of more oxygen. 1 5

b Contains chlorophyll to trap energy from sunlight orcontains chlorophyll for photosynthesis. 1 5

2 a i To reach many parts of the soil. 1 5ii Give a large surface area for absorption. 1 5

b To grow or make proteins. 1 5

3 a C or carbon dioxide + water → glucose + oxygen 1 6

b A or oxygen + glucose → carbon dioxide + water 1 6

c 6H2O + 6CO2 → C6H12O6 + 6O2 (One mark for H2O and O2 in correctspace, one mark for balancing correctly, no marks for only one correctwithout balancing.) 2 7

4 a Any suitable example, e.g. wood for burning. 1 5

b Photosynthesis 1 6

5 a Any two from: 2 6Photosynthesis uses light energy or water or carbon dioxide; respiration releases energy or produces water or produces carbon dioxide.Photosynthesis produces glucose or oxygen; respiration uses glucose or oxygen.Photosynthesis needs chlorophyll; respiration does not need chlorophyll.

b Light or sunlight or the Sun. 1 6

c Add iodine solution – the starch in biomass turns black. 1 6

6 a Gives a large surface area compared with its volume. 1 7

b Lots of chloroplasts. 1 7Cells situated near upper surface of leaf. 1 7

7 a Rate of photosynthesis would increase (more reactant for the reaction). 1 7*

b Rate of photosynthesis would decrease. 1 7*

8 a Need to leave enough time for the experiment to stabilise/snails and plants respire slowly. 1 6

b No, she has only tested it in the light. 1 6

c Repeat the experiment, keeping the tube in the dark. 1 6

d Have an identical control tube but with no organisms. 1 7Repeat the experiment with fresh snails and waterweed. 1 7

Scores in the range of: NC Level

6–10 5

11–15 6

16–18 7

19–25 7*


C Pupil checklistPlants and photosynthesis


Learning outcomes I can do I can do I need to this very this quite do more well well work on this

I can describe photosynthesis.

I can name the reactants of photosynthesis and I know where they come from.

I can name the products of photosynthesis.

I can identify the special features of leaves that help them photosynthesise.

I can write a word equation for photosynthesis.

I can write a symbol equation for photosynthesis.

I can identify variables that may be important when investigating photosynthesis.

I can describe how roots take in water and nutrients from the soil.

I can identify the special features of roots that help them take in water and nutrients from the soil.

I can identify the ways in which plants use water.

I can describe the ways in which plants use glucose.

I can describe how new materials (biomass) can be made from glucose.

I can describe how photosynthesis and respiration affect the oxygen and carbon dioxide levels in the air.

I can describe how cutting down the rainforests can affect climate and living things.

I can relate my ideas about photosynthesis and respiration to wider environmental issues.

Pupil-Checklist.qxd 17-Jun-04 8:00 PM Page 3

C GlossaryPlants and photosynthesis


Word

chlorophyll

fertiliser

leaf

photosynthesis

root

root hairs

stomata R

veins

Definition

Plants make food by photosynthesis. They turn carbondioxide and water into sugars and oxygen, using lightenergy.

A plant organ that is important for photosynthesis.

A green substance in plants that is needed forphotosynthesis.

Holes in a leaf’s surface. Gases get in and out of the leafthrough stomata. R

A plant organ that takes in water and minerals from the soil,and anchors the plant in the soil.

Tiny structures on a root that absorb water from the soil.

A substance used to keep soil fertile, so that plants have allthe mineral salts they need to grow.

In plants, these tubes transport water, minerals and sugarsaround the plant.

Glossary.qxd 18-Jun-04 11:33 AM Page 4

C Key wordsPlants and photosynthesis

chlorophyll

fertiliser

leaf

photosynthesis

root

root hairs

stomata R

veins

chlorophyll

fertiliser

leaf

photosynthesis

root

root hairs

stomata R

veins

Sheet 1 of 1

Sheet 1 of 1


Key wordsC Plants and photosynthesis


Keywords.qxd 18-Jun-04 11:35 AM Page 3


C Book answersPlants and photosynthesis

C1 Hungry plantsGreena Andrew and Jenny.b i Carbon dioxide and water.

ii Glucose and oxygen.c The living room.d The plant in the living room can

photosynthesise more quickly because there ismore light there.

1 a Plants make food by a process calledphotosynthesis.

b Plants get light energy from the Sun.c Most photosynthesis happens in the leaves.d Photosynthesis produces sugar and oxygen.

2 a Photosynthesis would stop.b Photosynthesis would stop.

3 There would not be enough oxygen and toomuch carbon dioxide would accumulate tosupport human life.

Reda Andrew and Jenny.b Do experiments in which you stopped, in turn,

sunlight, carbon dioxide and water fromreaching the plant.

c The mass of the tree increased much more thanthe loss of mass in the soil. This tells us that thetree gained its mass from materials outside the soil.

d From the carbon dioxide and water in the air.e The plant in the living room can

photosynthesise more quickly because there ismore light there.

f Photosynthesis stopped between (about) 18:00and 05:00 hours. The carbon dioxide levelstayed high and the oxygen level stayed lowduring these hours.

g Between (about) 08:00 and 15:00 hours.h Between 18:00 and 05:00 hours.1 To produce the food they need to grow.2 There would not be enough oxygen in the

atmosphere without plants to support humanlife. Too much carbon dioxide would accumulateto support human life without plants.

3 a There were fewer bubbles produced each minute.b The speed of photosynthesis decreased.c The plant is synthesising as fast as it can.

C2 A food factoryGreena A large surface area gathers more light. Being thin

allows the light to penetrate into the solar cell.b So they will be able to use a large amount of the

Sun’s energy.c So that the sunlight will penetrate into the leaf.d oxygene More sunlight can reach the cells near the top

where photosynthesis occurs.1 Photosynthesis happens in the chloroplasts in

the leaf. Leaves are broad and flat to take in a lot

of light energy. Leaves have holes in to letgases in and out. Leaves have a waxy topsurface to stop water being lost.

2 a chloroplastsb They can pack together closely making sure

they catch as much light as possible.3 The carbon dioxide for photosynthesis goes into

the leaf through the stomata. The oxygen madeby photosynthesis moves out of the palisadecells, into the stomata and then out of the leafand into the air.

Reda They are both broad and thin.b They need to gather more light in the shade so

they have broader leaves.c So that the sunlight can penetrate into the

palisade cells.d The veins transport water around the leaf.e The carbon dioxide from the air passes through

the guard cells into the stoma and then diffusesinto the palisade cells where it is used by thechloroplasts to make glucose and oxygen.

1 Large, broad and thin2 a They contain chloroplasts.

b They have a large surface area so that everycell receives as much sunlight as possible.

c To let the gases move around the leaf.3 a They allow gases to pass in and out of the

leaf from the atmosphere.b They change shape to open or close each

stoma. By doing this they control theamount of carbon dioxide and oxygen thatgoes in and out of the leaf.

4 a Only in the cells that contain chlorophylltowards the centre of the leaf.

b Food dissolves in water and is carriedthrough the veins to other parts of the plantso the plant’s cells can use it.

C3 Don’t dry up!Greena Water is needed for photosynthesis, it carries

nutrients around the plant and it keeps theplant upright.

b They keep the plant healthy.1 a To be used in photosynthesis and to carry

nutrients around to all cells in the plant.b They help the plant to stay healthy and

photosynthesise more efficiently.2 a To take in water and nutrients from the soil.

To hold the plant firm in the soil.b They have a large surface area.

3 Individual answers.

Reda Water is used in photosynthesis. It carries

nutrients around the plants through the veins sothat all cells get the food they need to stay alive.

Book Answers.qxd 18-Jun-04 12:44 PM Page 7


C Book answersPlants and photosynthesis (continued)

b i Root hair cells are specialised cells that stickinto the soil, giving a large surface area,which helps the roots take in water from thesoil more quickly.

c i The plant will wilt.ii The root cells won’t get any oxygen and

will die.d All the plant’s cells need glucose for respiration.1 a A water droplet follows the route from the

soil into the root hair cells, root, stem, veins,spongy layer, palisade cell.

b To carry out photosynthesis and to transportnutrients around the leaf.

2 a So that they get water from a long distancefrom the plant and so that they have a largesurface area to absorb water.

b So that they can absorb water quickly.c The hairs are very fine and poke into the soil

giving a large surface area.

C4 Using plant biomassGreena biomassb From the Sun, from glucose used to make plant

materials and from the mass of animal material.c For eating, for building houses and furniture, for

making clothes, etc.1 The total mass of a living thing, not ... including

water, is called the biomass.Starch ... is made from glucose.Biomass can be stored in ... the roots, stem orleaves.Photosynthesis makes glucose which ... makesother substances.

2 To make leaves, stems, flowers, seeds and roots.3 Individual answers.

Reda Fossil fuels, oil, coal and gas.b biomassc Protein, fat, carbohydrate, vitamins and minerals.d For eating, for building houses and furniture, for

making clothes, etc.1 Biomass is the total mass of plant or animal

material, not including water.2 To help them survive.3 Individual answers.4 a Any four of: leaves, stems, flowers, seeds, roots.

b The Sun.5 The glucose made in a plant by photosynthesis

is joined together to make starch. The starch isstored in roots, stems and leaves to help themsurvive into the next year.

C5 Spot the differenceGreena They are the same.b i In every cell of the plant.

ii In the leaves.

c Carbon dioxide.d oxygene Trees which have been cut down will not use the

carbon dioxide for photosynthesis. The carbondioxide levels will go up as the gas accumulatesin the atmosphere.

f Oxygen is needed by plants and animals forrespiration.

1 a Respiration happens in every cell of everyanimal and plant.

b Cutting down rainforests may make carbondioxide levels go up in the air around theworld.

c Photosynthesis happens in plants duringthe day when it is light.

d Respiration happens during the night andthe day.

2 Day Nightgives out carbon dioxide � �takes in carbon dioxide � ✗gives out oxygen � ✗takes in oxygen � �

3 Because they give out carbon dioxide gas onlywhich is not healthy for a person recoveringfrom an illness.

Reda i The reactants in photosynthesis are the same

as the products in respiration.ii Photosynthesis uses energy but in respiration

energy is released.b Plants photosynthesise during the day and

respire all the time. Carbon dioxide is given outall the time so respiration must be happeningall of the time.

c Carbon dioxide.d oxygen

The carbon dioxide levels went up very slowlyin the 1700s but they went up very quickly inthe 1900s.

e They would decrease.1 a Respiration occurs all of the time in living

plants and animals.b Respiration occurs in plants all of the time.

2 Day Nightgives out carbon dioxide � �takes in carbon dioxide � ✗gives out oxygen � ✗takes in oxygen � �

3 Because they give out carbon dioxide gas onlywhich is not healthy for a person recoveringfrom an illness.

4 The level of carbon dioxide increases at nightand decreases during the day. The oxygen levelincreases during the day and decreases at night.

5 a The oxygen level will decrease and thecarbon dioxide level increase.

b The oxygen level will increase and the carbondioxide level will decrease.

Book Answers.qxd 18-Jun-04 12:44 PM Page 8

c plants and photosynthesis unit guide -...

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