Gas exchange in plants

Question 1

What happens to a plants gas exchange during the day?

Answer 1

Higher light intensity so more photosynthesis

Respiration is slower so net uptake of carbon dioxide and net release of oxygen

Question 2

What happens to plants gas exchange at night?

Answer 2

Little to no light so little photosynthesis

Respiration is faster so net uptake of oxygen and net release of carbon dioxide

Question 3

Where does gas exchange occur in plants?

Answer 3

Occurs between air spaces in the leaves and the atmosphere. Carbon dioxide and oxygen diffuse, moving through to the stomata

Question 4

How is a leaf specialised for gas exchange?

Answer 4

Leaf is thin so diffusion distance is short
Large surface area so larger number of stomata which increases carbon dioxide diffusion
Guard cells can change shape so they can close to prevent water loss if it has lost too much water