FilamentAnther

StigmaStyle

Ovary

Carpel

PetalSepal

Ovule

Stamen

Section 24-1

Figure 24–5 The Structure of a Flower

I. Carpel – female a. Stigma – traps pollem b. Style supports stigma;

forms a pollen tube c. Ovary – becomes fruit d. Ovule- becomes seeds

II. Stamen – male a. Anther- produces

pollen b. Filament- supports

antherIII. Petals – attract pollinators IV. Sepals – protect flower bud

while it is developing

From flower to fruit

Flowers, fruits and seeds…

III. Why are seed plants more successful that spore producing plants?

A. Gametophyte generation is very tiny (only a few cells). In gymnosperms and angiosperms it is protected inside seeds and fruits so the young of seed plants tend to survive better. The spores of ferns and mosses must land in a wet habitat. If they do not, they will die.

B. Sperm does not have to swim thru water- it is carried by wind or animals during pollination. This enables seed plants to live in dryer habitats. It also increases reproductive success.

Name 5 Characteristics all Plants share

•Eukaryotic

•Cell Wall of Cellulose

•All Multicellular

•Autotrophs- Use Photosynthesis

•Reproduce Sexually and Asexually

Scientist believe all plants probably evolved from what common ancestor?

Freshwater Multicellular Green Algae

FloweringplantsCone-bearing

plantsFerns and

their relativesMosses and

their relatives

Green algaeancestor

Flowers; SeedsEnclosed in Fruit

Seeds

Water-Conducting(Vascular) Tissue

What evidence suggests that all plants probbably evolved from a multicellular green algae?

1. Similar life cycles (alternation of generations)

2. Cellulose in cell walls3. Similar pigments; like chlorophyll4. DNA evidence

What group of plants has NO Vascular tissues and relies on water for reproduction because it doews not produce seeds?

Bryophytes

What group of plants has has vascular tissue but still relies on water for reproduction because it does not produce seeds?

Ferns and their relatives

This group of plants were the first to produce seeds allowing plants to live away from water sources.

Gymnosperms

This group of plants is the most successful because of their ability to produce flowers and enclose their seeds within a fruit.

Angiosperms

Plant Structures and Tissues

Floweringplants

Cone-bearingplants

Ferns andtheir relatives

Mosses andtheir relatives

Green algaeancestor

Flowers; SeedsEnclosed in Fruit

Seeds

Water-Conducting(Vascular) Tissue

Section 22-1

Figure 22–6  A Cladogram of Plant Groups

Go to Section:

Gametophyte (N)

Sporophyte (2N)

Bryophytes Ferns Seed plants

Section 24-1

Figure 24–1 Evolution of the Gametophyte and the Sporophyte

Seed coat

Embryo

Storedfood supply

Seed

Wing

A

B

Section 22-4

Figure 22–19 The Structure of a Seed

Go to Section:

Basic Structures in Plants

A. Seed – embryo of a plant that is protected by a covering and surrounded by a food supply

1. Can remain dormant for many years2. Environmental factors (temperature and

moisture) end dormancy

3. Many modified for easy dispersal

a. Light weight - can float in water and in the air

b. Textured seed coats that stick to animal fur

c.“Winged” seeds – can “fly” long distances away from parent plant

d. Angiosperm seeds are surrounded by fleshy fruits that are eaten by animals allowing seeds to be dispersed

e. Seeds of Gymnosperms develop inside of protective cones

Section 23-2

Figure 23–7 The Structure of a Root

1. Xylem - transports water from the roots to the rest of the plant

2. Phloem - transports the products of photosynthesis (sugars) from the leaves to the rest of the plant

Vascular Tissues- system of “tubes” throughout a plant; two types – xylem and phloem

Section 23-2

Epidermis

Ground tissue(cortex)

VascularCylinder

Root hairs

Phloem

Xylem

Apical meristem

Root cap

Zone of maturation

Zone of elongation

Figure 23–7 The Structure of a RootRoots – absorb water and nutrients, anchor the plant, store food

Dermal tissue

Vascular tissue

Ground tissue

Stem

Root

Leaf

Section 23-1

Stems – supports plant, contains vascular tissue to transport water and nutrients between the roots and leaves

1. Two types of growth occur in stems and roots

a. Primary – growth from the tips of the roots and the shoots at areas called apical meristem

b. Secondary – growth in the width of the plant. (tree rings)

Section 23-5

Evaporation of water molecules out of leaves.

Pull of water molecules upward from the roots.

A B

Transpiration

E. Leaves carry out photosynthesis and transpiration

1. Epidermis - outer layer that covers the leaf. “skin”

2. Cuticle – waxy covering over the epidermis that prevents the plant from drying out

3. Mesophyll - middle layer of cells that carry out photosynthesis and exchange of the gases CO2 and O2

Section 23-4

Veins

XylemPhloem Vein

Cuticle

Epidermis

mesophyll

Epidermis

Stomata

Guardcells

mesophyll

Figure 23–18 The Internal Structure of a Leaf

4. Stomata – openings on the bottom of the leaf that allow gases to enter and leave

5. Guard cells – cells around the stomata that open and close the stomata

When the guard cells are full of water, the stomata is open. When they do not have water the stomata is closed. (This helps the plant conserve water when it is dry. Stomata are usually closed at night. (no sun = no photosynthesis)

Section 23-4

Veins

XylemPhloem Vein

Cuticle

Epidermis

mesophyll

Epidermis

Stomata

Guardcells

mesophyll

Figure 23–18 The Internal Structure of a Leaf

23-4 Structure and Function of Leaves

F. Flowers – reproductive structures present only in Angiosperms. Pollination – occurs mostly by animals (best adaptation!) Many angiosperms have mutual relationships with animals like insects, bats, or birds. As animals gather nectar from flowers, they also transfer pollen from flower to flower helping the plant reproduce. Many animal species are flower specific- they only gather nectar from one type of flower. After pollination and fertilization, seeds develop inside protective fruits.

FilamentAnther

StigmaStyle

Ovary

Carpel

PetalSepal

Ovule

Stamen

Section 24-1

Figure 24–5 The Structure of a Flower

I. Carpel – female a. Stigma – traps pollen b. Style supports stigma;

forms a pollen tube for sperm to reach egg

c. Ovary – becomes fruit d. Ovule- eggs that

becomes seedsII. Stamen – male

a. Anther- produces pollen b. Filament- supports

anther c. pollen – carries sperm

III. Petals – attract pollinators IV. Sepals – protect flower bud

while it is developing