Hydrophytes/Xerophytes Flashcards Preview

Biology module 3 > Hydrophytes/Xerophytes > Flashcards

Flashcards in Hydrophytes/Xerophytes Deck (23)
Loading flashcards...
1
Q

What are hydrophytes?

A

Plants adapted to live in aquatic habitats. They don’t need to reduce water loss however, they need adaptations to live with a low oxygen level.

2
Q

What is an example of a hydrophyte?

A

Water lillies

3
Q

How do air spaces help hydrophytes?

A

They help the plant float, increasing the amount of light/oxygen they recieve.
Can also store oxygen for respiration.

4
Q

How do the stomata differ in hydrophytes?

A

Only present on the upper surface of floating leaves to maximise gas exchange.

5
Q

How do flexible stems and leaves help hydrophytes?

A

Supported by the water around them so don’t need rigid stems,
Flexibility also prevents them from being damaged by water currents.

6
Q

Why do hydrophytes have few root hair cells?

A

Less water absorption is needed than other plants.

7
Q

Why do hydrophytes have a large surface area to volume ratio?

A

So they can absorb lots of light

8
Q

Why do hydrophytes’ seeds/shoots grow quickly?

A

In order to get to the oxygen in the air needed for photosynthesis.

9
Q

Why do hydrophytes have a thin waxy cuticle?

A

Don’t need to reduce water loss

10
Q

Why are stomata always open in hydrophytes?

A

More gas exchange can occur

Help lose water

11
Q

What are aerenchyma and how do they help hydrophytes?

A

Tubes that take oxygen in air down to the roots where respiration occurs for ATP so active transport of mineral ions can occur.

12
Q

What are xerophytes?

A

Plants adapted to live in dry climates. Their adaptations prevent them losing to much water by transpiration.

13
Q

How can stomata be adapted in xerophytes?

A

Stomata can be sunk in pits, sheltering it from wind, slowing down transpiration.
Can close stomata at hottest times of day when transpiration is at it’s highest.

14
Q

How does a layer of hair on the epidermis help xerophytes?

A

Traps a moist layer of air around the stomata, called a boundary layer, reducing the water potential gradient between the air and leaf.

15
Q

How does coiling their leaves when it’s hot/windy help xerophytes?

A

Traps moist air.
Reduces exposed surface area for losing water.
Protects stomata from wind.

16
Q

Why do xerophytes have a thick waxy cuticle on the epidermis?

A

Reduces evaporation as it is waterproof so water can’t pass through it easily.

17
Q

Why do cacti have spines instead of leaves?

A

Reduces surface area for evaporation

18
Q

Why do xerophytes have a small surface area to volume ratio?

A

Small surface area for evaporation

19
Q

What are the 2 things xerophyte roots can be?

A

Close to the surface - absorb water quickly

Deep - to get underground water.

20
Q

Why do xerophytes have fleshy stems?

A

To store water

21
Q

What is special about xerophyte parenchyma?

A

They can store water

22
Q

Why do xerophytes have a folded lower epidermis?

A

Increases boundary layers`

23
Q

What does deciduous mean?

A

Lose leaves in winter