1

Plant Characteristics:

 Multicellular  Eukaryotic  Autotrophic  Sessile means cannot move  Have cellulose in their cell walls

chloroplast vacuole

Golgi Cell wall body nucleus mitochondria

Cell membrane

2

2 stages to photosynthesis

STAGE 1 THE LIGHT REACTION CHLOROPLASTS CAPTURE ENERGY FROM THE SUN

3

STAGE 2 THE DARK REACTION

LIGHT ENERGY USED TO PRODUCE

SUGARS AND O2

FROM H20 AND CO2

4

PLANT LIFE CYCLE

Sporophyte plant = 2N

Spores are 1N

Zygote = 2N

Gametophyte plant = 1N

ALTERNATION OF GENERATIONS

ALTERNATE PHASES (2N & 1N) IN PLANT LIFE CYCLE

 FERTILIZATION= EGG + SPERM (the joining together of the

egg and sperm

5

 1N = Haploid = ½ the chromosomes

 Gametophyte = 1N

 2N = Diploid = full set of chromosomes

 Sporophyte = 2N

ZYGOTE= SPERM + EGG (it’s the product of fertilization) =2N (diploid) it’s a fertilized egg!!

 Plants evolved from the GREEN ALGAE (PROTISTA)  Contain chlorophyll a+b  Fossil evidence (440,000,000 years ago)

6

Adaptations which allowed plants to grow on land:

 Cuticle – waxy covering to prevent water loss o Keeps plant from drying out

 Modified leaves (Shapes & Stomata) Broad flat leaves better for photosynthesis

Leaves placed for best light absorption

Stomata for better gas exchange **Opening in the underside of the leaf

 Roots – take in water and anchor the plant

 Stem – support for growth and food storage

7

 Vascular development – transport food and

water

*simple plants use only diffusion

height limited!!

Vascular system allows water and nutrients

to go to the whole plant

now can be TALL plants!! Gametes are the sex cells  Seed development – protects gametes

 Alternation of generations (Sporophyte &

Gametophyte)

 Sexual reproduction

8

Two major groups

1. NON VASCULAR PLANTS

No developed system for transporting H2O &

nutrients

Must get H2O DIRECTLY from their

surroundings Plants are small, LOW TO THE

GROUND and must live in shady, DAMP

places

Hornwort Liverwort

9

2. VASCULAR PLANTS

Have a transport system!!

Now can live on Dry Land!

Vascular tissue provides

. Support

. Strength

. Stability

Plants without seeds

NON VASCULAR PLANTS Phylum Bryophyta

Low growing (short) plants

Live in moist (wet) areas =get water from surroundings

Water needed for reproduction

10

EXAMPLES OF NON VASCULAR NO SEEDS:

Mosses: very diverse group, found everywhere

. GAMETOPHYTE GENERATION SEEN

11

Liverwort –named for the gametophyte

Hornwort-named for the sporophyte

12

SEEDLESS Vascular Plants

Characteristics:

Have VASCULAR tissue Reproduce using SPORES Tall plants Grows in moist surroundings

Examples:

Ferns: cuticle upper surface

blade

Rhizome Roots

Underground stem of a fern GROUPS OF SORI SPORES

13

CLUB MOSSES

HORSETAIL

______

14

2 Types:

 Xylem: transports water

 Phloem: transports food (from photosynthesis)

15

YAY!! Now H2O NOT needed for fertilization!!!

This is a BIG DEAL. Plants can now move away from the edge of the water.

 POLLEN is now the sperm cell (male)

 SEEDS

o occur after fertilization

Egg + Pollen = Seed

 Definition: Seeds are structures that contain a young plant inside a protective covering

STOPS THE SEED FROM DRYING OUT

16

3 MAIN PARTS

EMBRYO COTYLEDONS SEED COAT • Has all the • can be stored • keeps main parts of food embryo from the adult • seed leaf drying out plant • allows seed to remain inactive for long periods

CORN

STEM

ROOT

17

***Must have enough water! Seed absorbs H2O***

 Embryo begins to grow again and pushes out of the seed  Roots grow DOWNWARD  Stems grow UPWARD

*** SEEDS CALLED SEEDLING ONCE THE PLANT’S LEAVES ARE SEEN***

18

NEEDED FOR SUCCESS OF PLANTS

(private life of plants “travelling” 10:05-22)

Animals o Attachment o Digestive tract (elephants, birds)

H2O Wind Ejection

ROOTS

Function: 1) Anchor plants

2) Absorb H2O & minerals for

Soil

3) Sometimes store food

19

2 types of roots

Fibrous Roots Tap Root

Dense tangle One LONG One LONG, main root of roots, Thick main takes lots of Smaller roots root branch off dirt with it Smaller roots when pulled Example: branch off

out Carrots & Example

Example: Carrots, & Dandylions Lawn grass Dandylions

Corn & Onions

Root Structure

Root cap: protects the root from injury

Dividing cells: area of new growth

20

Root hairs: increase water absorption and minerals absorption by increasing the surface area Root hair

Area of dividing cells = MITOSIS

ROOT CAP

See page 267

Function:

Support the plant (so leaves can get the most sun

21

Carries substances between the leaves and root

Two types of stems

Herbaceous Stems: -soft stems -example: pepper plants Woody Stems: -Hard, rigid stems -Example: roses, trees

Annual Rings:

Each ring of system (a band of light wood and a band of dark wood) represents one year’s growth

22

LEAVES

Cuticle

Upper leaf cells

Lower leaf cells xylem VEIN Stomata phloem

Upper leaf cells:

The most chloroplasts are located here Tightly packed together

23

Lower leaf cells:

Widely spaced cells allows CO2 to reach cells for photosynthesis

Stomata:

“mouth” tiny openings that allow gases to enter and exit the leaf

Stomata close to retain H2O

1 2 GYMNOSPERMS ANGIOSPERMS

Flowering plants "Naked" seeds seeds are oldest type of protected by seed plant fruit

24

Gymnosperms Naked seeds

 Cycadophyta (Cycads – produce male & female cones)  Ginkgophyta (Ginkgo – seeds on female trees smell really bad)  Coniferophyta (Conifers)  Gnetophyta

Ginko

Cycad

Conifers

Cycad Cones (2 male 1 female)

25

female pine cone

Male pine cone

Anthophyta (Flowering / fruit plants (250 000 species)

Characteristics All produce Flowers All produce seeds that are covered in Fruit

26

STRUCTURE OF FLOWERS

STAMEN

PISTIL

OR

CARPAL

Stamen:

Male reproductive structure

Anther produces the pollen Filament

27

Pistil:

Female reproductive structure

Stigma: sticky tip Style: connects the stigma and ovary Ovary: hollow structure that contains the ovules (developing seed)

REPRODUCTION IN

ANGIOSPERMS

1. Pollination (grain of pollen falls onto the stigma) 2. Fertilization(takes place in the ovary- Once fertilized the ZYGOTE begins to develop into the seeds embryo) 3. Fruit development and seed dispersal (after fertilization the ovary changes into the fruit)

28

Fibrous Tap root root

29

Definition: a plant’s growth response toward or away from a stimulus

Three important tropisms

Thigmotropism Phototropism Gravitropism

• Response to • Response to touch • Response to gravity • Vines coil light • Roots have a due to a (+) • Plants have a (+) response response (+) response • Stems have a (-) response

Hormones:

Chemicals that affect growth and development

30

Photoperiodism:

A plant’s response to seasonal changes in the length of night and day

Short day/long night Fall flowers Long day/short night Summer flowers Day neutral Not sensitive to periods of light and dark Ex: dandylions

Dormancy: period when an organism’s growth or activity stops

31

LIFE SPAN OF ANGIOSPERMS

Annual

complete life cycle in one season example: impatiens

Biennial

complete life cycle in 2 years 1st year develop roots and short stems 2nd year grow taller, produce flower & seeds then die Ex: parsley and celery

Perennials

Live more than 2 years

32