Plant structure adaptations and responses

Page
3

What is the result of pollination?

A Fruit: An ovary containing seeds.

Slide 16

Chapter 25

Plant

Responses and Adaptations

Slide # 16

Slide 17

Slide #17

Hormone-producing cells

Target

cells

Movement

of hormone

Hormone Action on Plants

A. Plant cells can produce hormones: which are chemical messengers that travel throughout the plant causing other cells called target cells to respond.

B. In plants, hormones control:

Plant growth & development

Plant responses to environment

Cells in one blooming flower signals other blooms using hormones to open.

Slide 18

C. Plant cells will send signals to one another to tell them:

When trees to drop their leaves.

When to start new growth.

When to cause fruit to ripen.

When to cause flowers to bloom.

When to cause seeds to sprout.

Slide # 18

Leaf Drop

Fruit

Ripening

Sprouting

Corn Seeds

Cactus

Blooming

Tree Budding

Slide 19

Ethylene causes Fruit to Ripen

Fruit tissues release a small amount of ethlyene

Causes fruits to ripen.

As fruit become ripe, they produce more and more ethlyene, accelerating the ripening process.

Slide # 19

Ethylene released by apples and tomatoes causes fruit to age quickly.

Slide 20

Plant Tropisms

1. Tropism: the way a plant grows in response to stimuli in the environment.

Phototropism: growth response to light

-Plants bend towards light

Geotrophism: growth response to gravity

-plant roots grow down with gravity, shoots (stems) grow up against gravity and out of the soil.

Thigmotropism: growth response to touch

-vines grow up around trees, venus flytrap closes when leaves are touched

Slide # 20

Slide 21

Slide # 21

Geotropism

What type of tropism is shown in these pictures?

Thigmotrophism

Thigmotrophism

Geotropism

Phototropism

Phototropism