what is a plant? 1. multicellular 2. eukaryotic 3. cell walls of cellulose 4. carry out...

What is a Plant?What is a Plant?

1. Multicellular1. Multicellular

2. Eukaryotic2. Eukaryotic

3. Cell walls of 3. Cell walls of cellulosecellulose

4. Carry out 4. Carry out photosynthesisphotosynthesis

5. Store 5. Store energyenergy as as starchstarch

6. Autotrophic6. Autotrophic

ADAPTATIONS TO SURVIVE ON LANDADAPTATIONS TO SURVIVE ON LAND

1.1. To prevent water loss, many plants have–To prevent water loss, many plants have–

A. A. Waxy cuticle Waxy cuticle – thick layer for protection– thick layer for protectionB. B. Stomata Stomata – Open during day; close at night; – Open during day; close at night;

regulated by guard cells regulated by guard cells

2. 2. LeavesLeaves are specialized for are specialized for photosynthesisphotosynthesis

*Shape to trap light energy *Shape to trap light energy

*Gas exchange occurs here*Gas exchange occurs here

Organ of photosynthesis

is the leaf!

What is theorganelle?

3. Specialized roots for 3. Specialized roots for absorption of water absorption of water and minerals and minerals

4. Specialized 4. Specialized stemstem for for transporting transporting materials materials

5. Reproduction on lands needs to occur 5. Reproduction on lands needs to occur with little or no water with little or no water

****MANY PLANTS PRODUCE SPORES

****AND SOMEPRODUCE SEEDS

Evolution of Plants

• Using the following words, put them in order of how you think they evolved….

EVOLUTIONARY PERSPECTIVE OF EVOLUTIONARY PERSPECTIVE OF DEVELOPMENTDEVELOPMENT

OF PLANT TYPES:OF PLANT TYPES:

ALGAE ALGAE MOSSES MOSSES FERNS FERNS

CONE-BEARING CONE-BEARING FLOWERINGFLOWERING

TWO MAIN CATEGORIES OF TWO MAIN CATEGORIES OF PLANTS :PLANTS :

1. NONVASCULAR1. NONVASCULAR 2. VASCULAR2. VASCULAR

Examples of Nonvascular Plants -Examples of Nonvascular Plants -

LIVERWORTS

MOSSES

No vascular tissue!No vascular tissue!

Water moves by osmosisWater moves by osmosis

Low-growingLow-growing

Include 3 Main Groups:

A. Ferns(Seedless)

B. Gymnosperms (Seeds in cones)

C.Angiosperms (Seeds in flowers)

A. XYLEM - Cells in tubes that transport water and minerals

B. PHLOEM - Tubes that transport food

SugarsActively transported; water also moves(By osmosis)through the phloemfrom the SOURCE to the (Place thatstores or uses sugars) SINK

**PRESSURE FLOW HYPOTHESIS

Movementof water

Movementof sugar

Sugarmolecules

Source cell

Sink cell

Phloem Xylem

Phloem Transport

Vascular Plants Include 3 Main Groups:

A. Ferns(Seedless)

B. Gymnosperms (Seeds in cones)

C.Angiosperms (Seeds in fruits, Produce flowers)

A.Ferns –

Seedless Vascular plants

Require water for sperm to swim to egg

Leaves calledfronds

B. Gymnosperms

Vascular plants

Produce seeds on scales called cones

“Naked seeds”

***Water not neededfor reproduction

Pollen grain contains gametophyte and sperm!

Carried to female cone by wind, water, insects, ... (Pollination)

****Pollen grows tube to join egg

(fertilization) forming seed

Life cycle of gymnosperm

Most produce seeds in woody

cones

Female (seed)and

Male (pollen)cones

Seed coat

Embryo

Storedfood supply

Seed

Wing

A

B

 The Structure of a Seed

AFTER FERTILIZATION

Zygote becomes an EMBRYO (Diploid sporophyte)

COTYLEDONS – Seed leaf of embryo

SEED COAT – Protects embryo

Advantages of Seeds

*Food supply for growing plant*Protection by seed coat*Provides less competition with “parents”*Water not needed for fertilization

Largest Group of Gymnosperms are the Conifers

Needle – Like leaves help retain water

Flexible branches and needles so they don’t

break with the weight of snow!

A few are DECIDUOUS (Lose their leaves at

same time) so are dormant in winter

Most are EVERGREEN so can carry on

photosynthesis as soon as spring arrives

Grow tall because of wood tubes (tracheids) that

support water and dissolved minerals

Are these xylem or phloem???

**Bark reduces water loss

WHAT ARE ANGIOSPERMS?

VASCULAR PLANTSVASCULAR PLANTS

PRODUCE FLOWERSPRODUCE FLOWERS

DEVELOP SEEDS IN DEVELOP SEEDS IN FRUITS FRUITS WHICH HELPS PROTECT EMBRYOWHICH HELPS PROTECT EMBRYO

TWO CLASSES OF ANGIOSPERMS:

1. Monocots• One seed leaf in embryo

• Includes grasses, orchids, lilies, palms

•Parallel veins in leaves

• Flower parts in multiples of three

2. Dicots

• Two seed leaves in embryo

• Most flowering plants

• Leaves with netted veins

• Flower parts in multiples of four

or five

Monocot vs. Dicot

MonocotMonocot DicotDicot

CotyledonsCotyledons

(seed leaves)(seed leaves)

Mono=1Mono=1 Di=2Di=2

Leaf VeinsLeaf Veins ParallelParallel BranchedBranched

Flower Parts Flower Parts (#petals, (#petals, stamen, stamen, carpels, etc)carpels, etc)

Always in Always in multiples of 3multiples of 3

(ex. 3, 6, 9)(ex. 3, 6, 9)

In multiples of In multiples of 4s and 5s4s and 5s

RootsRoots fibrousfibrous Tap rootTap root

Monocot or Dicot????

Monocot or Dicot?

Monocots vs. Dicots

Absorption

Support; transport

Photosynthesis

Contain xylem and phloem

Two types of root systems:

A. TAPROOT SYSTEM – Large central roots, Ex: Carrot! (most dicots)

1. Roots

B. FIBROUS ROOT SYSTEM – Highly branched (Most monocots)

ROOT HAIRS increase surface area for absorption

ROOT CAP - Covers tip of the root and protects it

MERISTEM – Growth area just behind the root tip

~Was this primary or secondary growth?

Epidermis

Ground tissue(cortex)

VascularCylinder

Cross Section of Plant Root(magnification: 40x)

Ground tissue (cortex)

Epidermis

Endodermis

Vascular cylinder

Root hairs

Phloem

Xylem

Apical meristem

Root cap

Zone of maturation

Zone of elongation

Endodermis

Structure of a Root

2. STEMS

Two kinds –

A. HERBACEOUS – Flexible vascularbundles scattered

B. WOODY –

Rigid

Havegrowthrings of vasculartissue thatdetermine age

Wood Bark

Cork

Cork Cambium

Phloem

Vascular Cambium

Xylem: Sapwood

Xylem:Heartwood

Layers of a Tree Trunk

Contains old, nonfunctioningxylem that helpssupport the tree

Contains active xylem that transports water and minerals

Produces new xylem and phloem, which increase the width of the stem

Transports sugars produced by photosynthesis

Produces protective layer of cork

Contains old, nonfunctioning phloem that protects the tree

3. LEAVESA. SIMPLE – One leaf blade attached to stem

B. COMPOUND – Divided leaf blade attached to stem

PETIOLE – stalk that attaches leaf to stem

Cross Section of a Typical Leaf

MESOPHYLL – Ground tissue full of chloroplasts

PHLOEMXYLEM

GUARD CELLSTOMA

Epidermis

Cuticle

Guard cell

Stomata

Structure of a leaf: STOMATA

Structure of a Flower

1. SEPALS –

Leaflike; green; arranged in circle beneaththe petals

*Protectsthe ovary!

*Protects theFlower whileDeveloping!

2. PETALS –

Leaf-like and colorful to attract insects!

3. STAMEN – MALE!

Male part made of ANTHER and FILAMENT

Anther: produces pollen (sperm!)

Filament: stalk that supports the anther

4. PISTIL/CARPEL – FEMALE!

Female part made of sticky STIGMA (where pollen grains land), STYLE (transports sperm to egg), and OVARY which contains OVULES with eggs inside

COMPLETE FLOWER – Has all four

organs

INCOMPLETE FLOWER –

Lacks one or more organs

What is this picture missing?

FilamentAnther

StigmaStyle

Ovary

Carpel

PetalSepal

Ovule

Stamen

The Structure of a Flower

POLLINATION –

Transfer of pollen from the stamen to the pistil

Adaptations for Pollination that Attract Particular Animals:

1. Nectar2. Petal Color3. Scent

Types of Pollination

1. SELF-POLLINATION – Stigma receives pollen from the same plant

2. CROSS-POLLINATION2. CROSS-POLLINATION – – • POLLEN FROM ONE PLANTPOLLEN FROM ONE PLANT IS CARRIED TO STIGMA OF IS CARRIED TO STIGMA OF ANOTHER OF SAME TYPE OF ANOTHER OF SAME TYPE OF PLANT PLANT

• ALLOWS FOR EXCHANGE OFALLOWS FOR EXCHANGE OF GENETIC MATERIALGENETIC MATERIAL

After the pollen grain lands on the stigma, the pollen tube cell grows a tube to the ovary.

The two spermcells move through thetube intothe ovule

-One sperm joinswith the egg in theOvule.

-The other spermjoins with the central cell (2N) toform the endosperm (3N).

This process is called double fertilization!!!

Seed Formation

After fertilization occurs, the flower dies and the seed develops.

Ovule becomes the seed coat which protects the embryo.

The zygote divides becoming the embryo.

The 3N central cell develops into the endosperm which is food-storage tissue.

Fruits

The ovary develops into

the fruit!

Parts of a Seed

Fruits can be dry (Nuts and grains)or

Fleshy (Oranges, Peaches Tomatoes, Squash,…)

***Fruits protect the seeds and aid in dispersal***

Seed Germination

Seeds remain dormant until conditions are right for development and growth!

****GERMINATION – Development of the seed into a new plant!

Water, oxygen, and warm temperatures are Needed!

Root appears first, then the stem,

and finally the leaves

Growth and Development

Plants respond to stimuli from the environment This process is called TROPISM

POSITIVE TROPISM – growth towards the stimulusNEGATIVE TROPISM – growth away from the stimulus

PHOTOTROPISM – Response to light GRAVITROPISM –

Response to gravity

THIGMOTROPISM – Response to touch

PLANT HORMONES

HORMONES – Chemicals made in one part of an organism that cause a change somewhere else

*Produced in ROOTS!

AUXINS – Growth hormones; cause cells to elongate, inhibit growth of sidebranches

Control Tipremoved

Opaquecap

Clearcap

Opaque shiedover base

Highconcentration

of auxin

Lowconcentration

of auxin

Auxins and Phototropism

Apical meristem

Lateral buds

Apical meristem removed

Auxins produced in the apical meristeminhibit the growth of lateral buds.

Without the inhibiting effect of auxinsfrom the apicial meristem, lateral budsproduce many branches.

Apical Dominance

TAKS Review1. How are chloroplasts and mitochondria

alike?a. Get energy directly from the sunb. Found in humansc. Found in plantsd. Responsible for energy conversions

2. Plants give off oxygen in what process?a. Photosynthesisb. Aerobic respirationc. Chemosynthesisd. Anaerobic respiration

TAKS Review Cont….1. Production of Carbon Dioxide and sugar2. Production of Oxygen and sugar3. Exposure to light4. Breakdown of protein5. Intake of carbon dioxide6. Intake of oxygen

Three of the statements above are stages in photosynthesis. Select and arrange in order 3 stages of photosynthesis. a. 3-4-1b. 4-3-2c. 3-5-2d. 3-6-1

TAKS Review Cont….4. What are the function of stomata?

a. sugar production

b. protection

c. gas exchange

d. water storage

5. What is the function of xylem? Phloem?

a. transport water; transport food

b. transport food; transport water