3. Organisms Exchange Substances - Gas Exchange In The Leaf Of A Plant

Question 1

Describe 2 similarities between gas exchange in plants and gas exchange in insects:

Answer 1

• No living cell is far from the external air, and therefore a source of oxygen and carbon dioxide
• Diffusion takes place in the gas phase (air), which makes it more rapid than if it were in water

Question 2

Give 3 adaptations in leaves for rapid diffusion:

Answer 2

• Many small pores, called stomata, and so no cell is far from a stomata and therefore the diffusion pathway is short
• Numerous interconnecting air-spaces that occur throughout the mesophyll so that gases can readily come in contact with mesophyll cells
• Large surface area of mesophyll cells for rapid diffusion