Plant Responses

and

Adaptations

Plant Adaptations

Adaptations help plants survive (live and grow) in different areas(biomes). Adaptations - features that allow a plant or

animal to live in a particular place or habitat.

Adaptations of Plants

1. Absorbing Nutrients –absorb mineral nutrients from soil. (roots)

2. Preventing Water Loss -cuticle – watertight, waxy outer covering

-epidermis – outer layer of plant

-stomata –small openings

guard cells – cells around stomatas which help them to open.

3. Reproducing on Land –use pollen to reproduce

Adaptations of Plants4. Advantages of Conducting Tissues

- Vascular plants have tissues that transport water and nutrients.

5. Advantages of seeds

- Protection

- Nourishment

- Dispersal

- Delayed growth

6. Advantages of Flowers – Color/ scent help with pollination (reproduction)

WHAT ARE SOME ADAPTATIONS IN DIFFERENT

HABITATS?

Desert Adaptation

This plant has a waxy coating on its leaves to prevent water loss.

This cactus displays light-colored hair that helps shade the plant and hair to help shade the plant, reducing water loss.

Tropical Rainforest Plant Adaptation

Drip-tips on leaves help shed excess water. Broad leaves help get sunlight.

Prop roots help support plants in the shallow soil.

Temperate Rainforest Plant Adaptation 

Epiphytes live on other plants to reach the sunlight. Trees can grow very

tall in this very moist environment.

Temperate Deciduous Forest

Wild flowers grow in the spring before trees grow their leaves.

In the autumn, deciduous trees drop their leaves to minimize water loss. 

Temperate Deciduous Forest Plant Adaptations

Many trees have thick bark to protect against cold winters .

Broad leaves can capture a lot of sunlight for a tree.

Plant Growth & Responses

1. Plant cells produce hormones, which are chemical messengers, that travel throughout plant causing other cells called target cells to respond.

2. In plants, hormones control:

a) Plant growth & development

b) Plant responses to environment

c) Flower Blooming

Hormone-producing

cells

Target cells

Movement of hormone

A. Hormones in Plants

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

B. Plant cells will send signals to one another to tell them:1. When trees to drop their leaves.

2. When to start new growth.

3. When to cause fruit to ripen.

4. When to cause flowers to bloom.

5. When to cause seeds to sprout.

Leaf DropFruit Ripening

Sprouting Corn Seeds

Cactus BloomingTree Budding

Important Hormones

1.Gibberellins - responsible for plants growing into adult plants and flower growth

2.Ethylene – causes fruits to ripen

3.Auxins - responsible for geotropisms and phototropisms

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

D. Plant TropismsTropismTropism: the way a plant grows in

response to stimuli in the environment.1) Phototropism: growth response to light

Plants bend towards light

2) Gravitrophism: growth response to gravity plant roots grow down with gravity, shoots (stems) grow

up against gravity and out of the soil. Also called geotrophism

3) Thigmotropism: growth response to touch vines grow up around trees, Venus flytrap closes when

leaves are touched

Slide # 23

Gravitropism

What type of tropism is shown in these pictures?

ThigmotropismPhototropism

Phototropism

ThigmotropismGravitropism

Plants in our lives

Fruits and vegetablesCropsWoodmedicineFibers