grade 11 november 2015 life sciences p2

NATIONAL SENIOR CERTIFICATE

GRADE 11

NOVEMBER 2015

LIFE SCIENCES P2

MARKS: 150 TIME: 2½ hours

This question paper consists of 17 pages.

*ILFSCE2*

2 LIFE SCIENCES P2 (EC/NOVEMBER 2015)

Copyright reserved Please turn over

INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. Answer ALL the questions. 2. Write ALL the answers in your ANSWER BOOK. 3. Start the answers to EACH question at the top of a NEW page. 4. Number the answers correctly according to the numbering system used in

this question paper.

5. If answers are NOT presented according to the instructions of each question,

candidates will lose marks.

6. All drawings should be done in pencil and labelled in blue or black ink. 7. Draw diagrams, tables and flow charts ONLY when requested to do so. 8. The diagrams in this question paper may NOT necessarily be drawn to scale. 9. The use of graph paper is NOT permitted. 10. You may use a non-programmable calculator, protractor, and compass. 11. Write neatly and legibly.

(EC/NOVEMBER 2015) LIFE SCIENCES P2 3


SECTION A QUESTION 1 1.1 Various options are provided as possible answers to the following questions.

Choose the correct answer and write only the letter (A–D) next to the question number (1.1.1–1.1.10) in the ANSWER BOOK, for example 1.1.11 D.

1.1.1 The group(s) of plants that are dependent on water for reproduction

are: A Pteridophytes and Bryophytes B Bryophytes only C Gymnosperms only D Angiosperms and Gymnosperms 1.1.2 Gynaecium (pistil) consists of the … A stigma, style and ovary. B stigma, petal and ovary. C style, perigone and stamen. D style, petals and stamen. 1.1.3 An ovary would be found in ... A gymnosperms. B angiosperms. C bryophytes. D pteridophytes. 1.1.4 Saprophytic fungi derive nutrients from … A living organisms. B the atmosphere. C non-living organic matter. D both a and b. 1.1.5 Which of the following is NOT found in Pteridophytes? A Sori B Spores C Sporangia D Seeds



1.1.6 Study the following statements about eukaryotic cells and answer the question that follow.

Eukaryotic cells: (i) Are more complex than prokaryotic cells (ii) Have a membrane-bound nucleus (iii) Are believed to have evolved more recently than prokaryotic

cells (iv) Are usually smaller than viruses Which of the following statements is true about eukaryotic cells? A (i), (ii) and (iv) B (iii) and (iv) C (i), (ii), (iii) and (iv) D (i), (ii) and (iii) 1.1.7 Which part of a flower produces male gametes? A Petal B Ovary C Pollen D Ovule 1.1.8 Study the statements about sexual reproduction in plants and

answer the question that follow. (i) It generates variation in unstable environments (ii) Seeds facilitate dispersal of offspring to more distant locations (iii) Seed dormancy allows growth to be suspended until hostile

environmental conditions are reversed (iv) Offspring can be reproduced very rapidly Which statement is an advantage of sexual reproduction in plants? A (i), (ii), (iii) and (iv) B (i), (iv) C (ii), (iii) and (iv) D (i), (ii) and (iii) 1.1.9 Antibodies are proteins that... A break down pathogens. B catalyse biochemical reactions. C are produced by T-cells that kill disease-causing viruses. D bind with specific antigens.



1.1.10 Vaccination can control the spread of a(n) ... A genetic disorder. B infectious disease. C nutritional deficiency. D environmental disease. (10 x 2) (20) 1.2 Give the correct BIOLOGICAL TERM for each of the following descriptions.

Write only the term next to the question number (1.2.1–1.2.10) in the ANSWER BOOK.

1.2.1 The body plan of organisms, in which parts of matching size and

shape are arranged on either side or around an axis 1.2.2 Swelling at tip of the vertical hypha of Rhizopus in which spores

develop 1.2.3 Jelly-like layer between the ectoderm and endoderm 1.2.4 The removal of large quantities of trees so that conditions become

desert-like 1.2.5 Molecules consisting of three oxygen atoms 1.2.6 The term used to describe the concentration of nerve cells or sense

organs at the anterior end of the body 1.2.7 Type of asexual reproduction in which a bacteria splits in to two, as in

mitosis 1.2.8 The germ layer that gives rise to muscles and internal organs, other

than the gut 1.2.9 Substances that can be broken down naturally by micro organisms 1.2.10 The removal of soil by water or by wind (10 x 1) (10)



1.3 Indicate whether each of the statements in COLUMN Ι applies to A ONLY, B ONLY, BOTH A AND B, or NONE of the items in COLUMN ΙΙ. Write A ONLY, B ONLY, BOTH A AND B, or NONE next to the question number in the ANSWER BOOK.

COLUMN Ι COLUMN ΙΙ 1.3.1 Ectoderm, mesoglea and

endoderm A. Triploblastic B. Diploblastic

1.3.2 Carbon footprint can be reduced by

A. Recycling B. Reusing

1.3.3 Site constructed to dispose of waste

A. Reservoir B. Land fill

1.3.4 Factors decreasing water availability

A. Destruction of wetlands B. Exotic plants

1.3.5 The division of the body into a series of similar units

A. Cephalisation B. Segmentation

1.3.6 Animals that have a true body cavity

A. Coelomate B. Acoelomate

1.3.7 A circulatory system where blood flows in blood vessels

A. Closed blood system B. Open blood system

1.3.8 A process to exploit shale gas reserves in underground rock formation

A. Fracking B. Leaching

(8 x 2) (16)



1.4 Chloroflurocarbon (CFC) has unfortunately caused considerable damage to the ozone layer, resulting in the formation of big ‘holes’. Study the graph below showing the extent of damage (area of the ‘hole’) in the Antarctic ozone layer and answer the questions that follow.

1.4.1 During which year was the ‘hole’ in Antarctic area the: (a) Largest? (1) (b) Smallest? (1) 1.4.2 What was the area of the ‘hole’ (millions km2) in the years: (a) 2000 and (1) (b) 2005? (1) TOTAL SECTION A: 50



SECTION B QUESTION 2 2.1 Flowers are reproductive structures used for sexual reproduction in

angiosperm plants. Study the diagram below and answer the questions that follow.

2.1.1 Is this flower insect, wind, or bird pollinated? (1) 2.1.2 List THREE characteristics of this flower that make it well adapted

for your answer given in QUESTION 2.1.1. (3) 2.2 Angiosperms are a group of plants that produce seeds by means of sexual

reproduction. 2.2.1 What is the main advantage of sexual reproduction to plants? (1) 2.2.2 A seed bank in Norway has been storing seeds of a rare and

endangered plant. To keep the seeds fresh, 120 of the seeds of this plant were selected to be grown. Out of these 120 seeds, only 90 germinated. What percentage of the seeds was not fertile? Show all your working. (2)

2.2.3 Explain how each of the following features of seeds is important for

the plant’s survival: (a) Seeds can remain dormant for long periods of time. (1) (b) Some seeds contain endosperm tissue (1)



2.3 Study the phylogenetic tree below, taking note of how the four plant divisions have evolved and answer the questions that follow.

2.3.1 What is the ancestral form of all the plant divisions shown? (1) 2.3.2 Which plant division is the best adapted to life on land? (1) 2.3.3 Which plants are the most closely related? (2) 2.4 The World Health Organisation (WHO) collects data about diseases

worldwide. The table below shows data published by the WHO about the incidence of tuberculosis (TB) in the years 2000 and 2008, for four different income groups. Study the table and answer the questions that follow.

INCIDENCE OF TB PER 1 000 000 POPULATION Income Group In 2000 In 2008 Low 280 280 Lower middle 150 150 Upper middle 100 110 High 17 14 2.4.1 Using the information above, compare the data for 2000 and 2008 in

the four income groups. (4)

Phylogenetic tree showing plant evolution

Gymnosperms Moss Fern Angiosperms

Naked seeds Fruit

Enclosed seed

Flower

Cones

Pollen

Non vascular

Motile sperm

Seedless

Non-motile sperm

Seed

Root, stems, leaves

Vascular

Motile gametes

Algae



2.4.2 The highest incidence of TB is associated with the low-income group. Suggest THREE reasons why the incidence of TB is higher in the low-income group. (3)

2.5 The diagrams below show the natural greenhouse effect and enhanced

greenhouse effect. Study the diagrams and answer the questions that follow.

2.5.1 Name TWO main greenhouse gases. (2) 2.5.2 Why is it necessary for the natural greenhouse effect to be

maintained? (2) 2.5.3 Name ONE human activity that causes an enhanced greenhouse

effect. (1) 2.5.4 Explain ONE difference between the TWO diagrams above. (2)



2.6 Read the passage below, study the table, and answer the questions that follow. An environmental health officer from a local municipality received complaints

from residents living along a river, that there were dead fish floating in the river. The officer noticed a waste water treatment plant and a mine in the local area and that both released their waste into the same section of the river. The officer took SAMPLE A and SAMPLE B of the river water, from a point before and after the waste water treatment plant and mine released their waste into the river. The water samples were analysed in a laboratory. The table shows the results of the analysis.

TABLE: RESULTS OF ANALYSIS OF WATER. Substances/factors

found in samples SAMPLE A

(Taken before waste was released into river)

SAMPLE B (Taken after waste was

released into river)

Faecal coliforms (count/100ml) 500 130 000

Nitrate (mg/l) 1,6 5,2 Phosphate (mg/l) 0,1 0,9 Sodium (mg/l) 25 175 Chlorides (mg/l) 15 180 pH 6,7 3,5 2.6.1 Which THREE of the substances are most likely from the waste water

treatment works? (3) 2.6.2 Comparing the levels of faecal coliforms in SAMPLE A and SAMPLE

B, how well do you think the waste water treatment works are functioning? Give a reason for your answer. (3)

2.6.3 Name TWO waterborne diseases that are spread by untreated waste

water. (2) 2.6.4 Is the water in SAMPLE B more acidic, or more alkaline than the water

in SAMPLE A? (1) 2.6.5 Explain what is meant by acid mine drainage. (2) 2.6.6 Give TWO possible causes for the fish deaths in the river based on the

data in the table. (2) [40]



QUESTION 3 3.1 A student investigated the number of bacteria on the skin of people’s hands

after they washed and dried it. The same washing method was employed, but hands were dried either by using hot air from a hot air blower or by using paper towels. Swabs were used to take samples from the dried skin and bacteria were cultured from the swabs. The table below shows the number of bacteria that was cultured. Study the table and answer the questions that follow.

SAMPLES NUMBER OF BACTERIA (x108) PER SQUARE

CENTIMETRE (CM2) ON HAND SKIN FOLLOWING WASHING AND DRYING.

Air-dried skin Towel-dried skin 1 8,91 1,11 2 9,75 0,98 3 6,14 0,42 4 8,72 1,02 3.1.1 State the aim of the student’s investigation. (1) 3.1.2 Suggest THREE factors that must be controlled in this investigation to

make this a fair test. (3) 3.1.3 Write down the conclusion that the student could make, based on the

results of the investigation. (1) 3.1.4 Draw a bar graph to show the number of bacteria on four samples of

skin after they have been towel dried. (6)



3.2 The diagram below shows the movement of carbon dioxide into and out of the atmosphere. Study the diagram and answer the questions that follow.

3.2.1 Name a life process that: (a) Takes in carbon dioxide and (1) (b) Releases carbon dioxide (1) 3.2.2 What effect do increased levels of carbon dioxide in the atmosphere

have on the temperature of the atmosphere? (1) 3.2.3 Name the effect mentioned in QUESTION 3.2.2. (1)

3.2.4 What is a ‘carbon sink’? (1) 3.2.5 Give an example of a ‘carbon sink’. (1) 3.2.6 What would happen to the levels of carbon dioxide in the atmosphere if

‘carbon sinks’ were reduced? (1)

MOVEMENT OF CO2 IN THE ATMOSPHERE



3.3 A group of Grade 11 learners carried out an investigation to determine the impact that rotational harvesting would have on the long-term yield of Devil’s Claw plant. They compared Devil’s Claw densities over time for two different sites A and B. At site A, traditional healers divided the region into smaller areas. A different area was harvested each time. At site B, harvesters collected Devil’s Claw from any region (regular harvesting). Quadrats were thrown randomly in both areas to determine the density of Devil’s Claw for two consecutive years. The results are shown in the bar graph below. Study the graph and answer the questions that follow.

3.3.1 What is rotational harvesting? (1) 3.3.2 State ONE advantage of rotational harvesting. (1) 3.3.3 Write a hypothesis for this investigation. (2) 3.3.4 Present the results of the survey in a table format. (4) 3.3.5 What can you conclude from this study? (2)

9

4

0

1

2

3

4

5

6

7

8

9

10

Rotational harvesting Regular harvesting

Num

ber o

f pla

nts

harv

este

d

Harvesting method

Results of different harvesting methods of Devil's Claw

2007

2008



3.4 The diagram A below shows a complete animal while diagram B shows a cross section through the main body stalk. Study the diagrams below and answer the questions that follow.

3.4.1 Identify the phylum to which this organism belongs. (1) 3.4.2 Name the kind of symmetry shown in this organism. (1) 3.4.3 Explain the advantage this symmetry has for the mode of living of

this organism. (2) 3.4.4 Name THREE phyla that you have studied, which have a coelom. (3)



3.5 The diagram below shows two methods, which are used to give humans protection against diseases. Method A shows active immunity and Method B shows passive immunity. Method A can be used against polio. Method B is often used against tetanus.

Method A Method B Person receives small dose of

polio virus (antigen) Tetanus bacteria (antigen)

injected into an animal

Virus multiplies slowly in body Antibodies are made within

the animal’s body

Antibodies are made Blood removed from the

animal; used to produce a serum with antibodies

Second dose of weakened

virus given; more antibodies are made

Serum injected into a person infected with tetanus.

Tetanus antibodies are

weakened in the person’s body.

3.5.1 Name the substances that are produced by the body, which destroy

harmful viruses and bacteria. (1) 3.5.2 Why does Method A give long-lasting protection against polio? (1) 3.5.3 Method B does not give long-lasting protection against tetanus.

Why? (1) 3.5.4 In immunisation against polio, a second dose of the weakened virus

is given (known as a booster). Suggest why this booster is necessary. (1)

3.5.5 Why is Method B very good for dealing quickly with an infection like

tetanus? (1) TOTAL SECTION B: 80

METHODS USED TO GIVE HUMANS PROTECTION



SECTION C QUESTION 4 4.1 Write an essay in which you explain what is meant by the concept of food

security. Describe also the ways in which poor crop farming practices pose a threat to food security in South Africa. Finally mention how genetically modified food may help to address the problem of food shortage.

Content (17) Synthesis (3) (20) NOTE: NO marks will be awarded for answers in the form of flow charts or

diagrams. TOTAL SECTION C: 20 GRAND TOTAL: 150

NATIONAL SENIOR CERTIFICATE

GRADE 11

NOVEMBER 2015

LIFE SCIENCES P2 MEMORANDUM

MARKS: 150 TIME: 2½ hours

This memorandum consists of 9 pages.



SECTION A QUESTION 1 1.1 1.1.1 A 33 1.1.2 A 33 1.1.3 B 33 1.1.4 C 33 1.1.5 D 33 1.1.6 D 33 1.1.7 C 33 1.1.8 D 33 1.1.9 D 33 1.1.10 B 33 (10 x 2) (20) 1.2 1.2.1 Symmetrical 3/bilaterally symmetrical / radially symmetrical 1.2.2 Sporangia 3/ sporangium 1.2.3 Mesoglea 3 1.2.4 Deforestation 3 1.2.5 Ozone 3 1.2.6 Cephalisation 3 1.2.7 Binary fission 3 1.2.8 Mesoderm 3 1.2.9 Biodegradable 3 1.2.10 Erosion 3 (10 x 1) (10)



1.3 1.3.1 B only 33 1.3.2 Both A and B 33 1.3.3 B only 33 1.3.4 Both A and B 33 1.3.5 B only 33 1.3.6 A only 33 1.3.7 A only 33 1.3.8 A only 33 (8 x 2) (16) 1.4 1.4.1 (a) 2014 3 (1) (b) 1994 3 (1) 1.4.2 (a) 9 – 10 3 (1) (b) 17 – 18 3 (1) TOTAL SECTION A: 50



SECTION B QUESTION 2 2.1 2.1.1 Wind 3 (1) 2.1.2 - Produces large amount of pollen 3 to increase the chances of

pollination. - Pollen grains are light, smooth 3 and dry to allow them to float. - Anthers are attached to their filaments in such a way that they

are easily moveable with wind. 3 - Stigma is large, feathery and sticky to trap as much pollen as

possible. - Large anther - Small flowers without colourful petals. - Absence of petals / calyx for better exposure of pollen to wind. - Reduced scent and nectar. (Any 3 x 1) (3)

2.2 2.2.1 - It generates genetic variety. 3 (1) 2.2.2 - (120 – 90 = 30) 3 (30/120 x 100 = 25%) 3 (2) 2.2.3 (a) They survive unfavourable periods./Testa protects the

embryo. 3 (b) Provides food for the growing embryo 3 until the plant starts

to make food by means of photosynthesis. (2) 2.3 2.3.1 Algae 3 (1) 2.3.2 Angiosperms 3 (1) 2.3.3 Gymnosperm 3

Angiosperm 3 (2) 2.4 2.4.1 - In low income group it remained the same 3

- Low middle income group it remained the same 3 - Upper middle income group it increased by 10 per 1 000 000 3 - High income group it decreased by 3 per 1 000 000 3

(4)

2.4.2 - Overcrowded living space 3

- Poorly ventilated living space 3 - Poor diet 3/malnourished - Poor health 3/ more diseases like HIV / less immunity - Homelessness 3/ poverty - Medical treatment more difficult to access. 3 - Lack of awareness 3/ Lack of education (Any 3 x 1) (3)



2.5 2.5.1 - Carbon dioxide 3 and methane 3 (2) 2.5.2 - It traps sufficient heat to sustain life. 3/ keeps temperature at

favourable range. - Radiant energy is used for various life processes, such as

photosynthesis. 3 (2) 2.5.3 - Burning fossil fuels 3

- Land clearing 3/ deforestation (Accept any sensible answer) (Any 1 x 1) (1)

2.5.4 - Natural greenhouse effect releases more infrared rays 3 into

the atmosphere than enhanced greenhouse effect. 3 OR

- Natural greenhouse effect has less greenhouse gases 3 surrounding the atmosphere than enhanced greenhouse effect. 3 (2)

2.6 2.6.1 - Faecal coliforms, 3 nitrates 3 phosphates 3 (3) 2.6.2 - Not functioning properly, 3 because the level of faecal coliforms

increased greatly from sample A to sample B, 3 indicating that untreated wastewater is being released into the river. 3 (3)

2.6.3 - Cholera, 3 typhoid, 3 hepatitis, 3 gastroenteritis, 3dysentery 3

/ diarrhoea ect. (Any 2 x 1) (2) 2.6.4 - More acidic. 3 (1) 2.6.5 - Drainage of highly acidic water 3 from old mine shafts to the

surface of the land. 3 (2) 2.6.6 - Toxic levels of salts (sodium and chloride) 3

- Reduced oxygen levels 3 caused by the decomposition of water plants that grew rapidly due to eutrophication.

- pH level dropping 3/ water too acidic for fish to survive. (Any 2 x 1) (2)

[40]



QUESTION 3 3.1 3.1.1 - To find out which method of drying is better – air blowing or

towel drying. 3 OR

- To investigate the effect of two different methods of drying hands, after washing, on the number of bacteria on the skin of the hands. 3 (1)

3.1.2 - The atmospheric temperature / humidity in the testing venue. 3

- The time of wiping and exposure to the hot air. 3 - Using the same people for both methods. 3 - Using the same conditions for washing (e.g. amount of soap,

amount of water, time rinsing, etc.) 3 (Any 3 x 1) (3) 3.1.3 - Air-dried skin samples have a far greater number of bacteria

compared to towel-dried skin samples. 3 OR

- Towel drying is better than air blow drying. 3 (1) 3.1.4

Guideline for the assessing of the graph Correct type of graph 1 Title of graph 1 Correct label and scale of x-axis 1 Correct label and scale of y-axis 1 Plotting of bars 1 : 1 to 3 bars plotted correctly

2 : all 4 bars plotted correctly (6) NOTE: If axes are transposed, marks will be lost for labelling X-

axis and Y-axis.

1.11

0.98

0.42

1.02

0

0.2

0.4

0.6

0.8

1

1.2

1 2 3 4

Num

ber o

f bac

teria

(x1

08/c

m2)

Sample

Graph showing number of bacteria on four samples of towel dried skin



3.2 3.2.1 (a) photosynthesis 3 (1) (b) respiration 3 (1) 3.2.2 - Leads to an increase in the temperature of the atmosphere 3 (1) 3.2.3 - Global warming 3 (1) 3.2.4 - Something that absorbs carbon dioxide from the atmosphere. 3 (1) 3.2.5 - Green plants 3

- Trees 3/ timber - Forests 3 (Any 1 x 1) (1)

3.2.6 - Levels of carbon dioxide in the atmosphere would rise. 3 (1) 3.3 3.3.1 - Harvesting from a different section of the harvest area each

time. 3 (1) 3.3.2 - Gives the plant a chance to grow 3 (1) 3.3.3 - Rotational harvesting is a more sustainable 3method of

harvesting Devil’s Claw. 3 OR

- Regular harvesting is more sustainable 3 method of harvesting Devil’s Claw 3/ both are equally 3 sustainable. 3 (2)

3.3.4 Rotational harvesting Regular harvesting 2007 8 9 2008 9 4 *Correct heading of columns = 1 *Correct heading of rows = 1 *Correct entering of data = 2 (4) 3.3.5 - Rotational harvesting is sustainable 3 regular harvesting is

not. 3/ rotational harvesting is more sustainable. 33 (2) 3.4 3.4.1 - Cnidaria 3 (1) 3.4.2 - Radial 3symmetry (1) 3.4.3 - It can catch prey 3/ sense danger from all directions, because

they are sedentary 3/ sessile. (2) 3.4.4 - Chordata; 3 Arthropoda; 3 Annelida 3 (3) 3.5 3.5.1 - Antibodies 3 (1)



3.5.2 - Antibodies remain in the body 3/ are not weakened / last for a long time or are not destroyed / body continues to make antibodies / cause an increase in the number of antibodies / person has made own antibodies. (Any 1 x 1) (1)

3.5.3 - Antibodies are weakened after a short time 3/ antibodies are

made in an animal body / they are not human antibodies / person has not made own antibodies. (Any 1 x 1) (1)

3.5.4 - So that more antibodies are made 3/ to keep antibody count

high / so body keeps making antibodies for a long time. (Any 1 x 1) (1)

3.5.5 - Injection of ready-made antibodies 3/ does not have to wait for

antibody formation / has large amount of antibody quickly available / antibodies start working straight away. (Any 1 x 1) (1)

[40] TOTAL SECTION B: 80

SECTION C QUESTION 4 4.1 Food security. - The state of having reliable access 3 to a sufficient quantity of affordable,

nutritious food. 3 (2) Poor crop farming practices - monoculture 3 planting the same crop over and over 3 - because it is cost effective 3, but - it attracts more pests 3 and it - reduces quantity of crop produced 3 - this makes food more expensive to buy 3/ less affordable - pest reduce the quality of crop 3 making - it necessary to use more pesticides, 3 more money spent - pesticides / insecticides kill useful crops also 3 - pesticides are bad for human health 3/ affects nerves - they also cause pollution 3 and it - also reduces biodiversity 3 - monoculture causes top soil erosion, 3 leading to - more fertilisers to be used 3 - over fertilisation causes oxygen deprived soil 3 - leads to less production of crops 3 in future - and also produces greenhouse gases 3 - poor irrigation 3/ poor infrastructure used due to - lack of awerness 3/ education / experience / motivation Max. (10)



Genetically modified food - genes for desired traits are removed 3 from one plant and - introduced into another plant 3 to make better crop - examples of desired traits – resistance to diseases 3 - short maturity 3 - higher yield 3 - cheaper food 3 - increases nutritional value 3 - longer shelf life 3 - bigger and more attractive food, 3etc. - helps poor / starving / famine people 3 - to make food accessible and available 3 Max. (5) (17) Relevance (R) Logical Sequence (L) Comprehensive (C) All information provided

are relevant to the essay i.e only the 3 points are discussed.

Ideas are arranged in a logical manner i.e starting with food security followed by poor crop farming practices followed by genetically modified food.

In the body of the essay, minimum 6 relevant points out of the 10 for poor farming practices and a minimum of 3 points for genetically modified food are obtained.

Synthesis (3) TOTAL SECTION C: 20 GRAND TOTAL: 150

grade 11 november 2015 life sciences p2

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