Plants

Question 1

Name the gas exchange surface in plants

Answer 1

Mesophyll cells

Question 2

How is a large surface area achieved in plants?

Answer 2

Wide and flat leaves

Question 3

How is water loss reduced from the gas exchange surface?

Answer 3

Guard cells close stomata

Question 4

What’s the equation for photosynthesis?

Answer 4

Carbon dioxide water → glucose + oxygen
(Light energy)

Question 5

What is the respiration equation?

Answer 5

Glucose + oxygen → carbon dioxide x water

Question 6

Name the 6 ways leaves adapted for photosynthesis ?

Answer 6

Thin, lots of chloroplasts, wide and flat, veins, airspaces, stomata

Question 7

Why is being thin an adaption for photosynthesis?

Answer 7

It creates a short diffusion pathway and allows gases to reach cells easily

Question 8

Why is lots of chloroplasts an adaption for photosynthesis?

Answer 8

Located in the palisade layer of cels near the top of the leaf for light and air space for the gases

Question 9

Why is a leaf being wide and flat an adaption for photosynthesis?

Answer 9

Creates a large surface area to volume ratio to absorb as much light as possible

Question 10

How do veins allow for effective photosynthesis?

Answer 10

They carry water to the cells and carry glucose away and also support leaves

Question 11

How do air spaces allow for efficient photosynthesis?

Answer 11

They allow easy movement and exchange of gases

Question 12

How do stomata allow for efficient photosynthesis?

Answer 12

Allow gases in and out of the leaf

Question 13

Where are the stomata found?

Answer 13

On the underside of leaves

Question 14

What is each stoma surrounded by?

Answer 14

2 guard cells

Question 15

Explain what happens when the stoma is turgid

Answer 15

The guard cells curve outwards as they gain water, his opens the stoma, allowing gases in and out

Question 16

explain what happens when the stoma is flaccid

Answer 16

The guard cells move closer together as they lose water, which closes the stoma. This stops the movement of gases, but also prevents water loss by evaporation

Question 17

What are xerophytes?

Answer 17

Plants that are adapted to reduce water loss.

Question 18

In what 5 ways are plants adapted to reduce water loss?

Answer 18

Thick waxy cuticle, hairs on leaves, curled leaves, sunken / fewer stomata, reduced sa:v

Question 19

Why does a thick waxy cuticle reduce water loss?

Answer 19

It increases diffusion pathway so less chance of gas diffusing out. Helps to reduce water loss via evaporation as there’s increased thickness

Question 20

How do hairs on leaves help to reduce water loss?

Answer 20

They trap water vapour / moist air next to the leaf surface. Water potential gradient between inside and outside of leaf is reduced. Less water lost by transpiration

Question 21

How do curled leaves reduce water loss?

Answer 21

Stomata on lower epidermis are trapped with still air. No water potential gradient between inside and outside of leaf so transpiration is reduced

Question 22

How do sunken stomata or fewer stomata reduce water loss?

Answer 22

Traps water vapour next to the leaf and reduces the water potential gradient. Reduces air movement

Question 23

How does a reduced SA:V ratio help to reduce water loss?

Answer 23

No leaves means less SA and stomata. Slower rate of diffusion of gases