Gas Exchange

Question 1

How are leaves adapted for gas exchange? 5 reasons.

Answer 1

1) Large surface area to volume ratio - aids diffusion of gases into cells.
2) Air spaces inside of leaf - allows gases (CO2 and O2) to move more easily between cells and increases surface area for gas exchange.
3) Lower surface of leaf full of stomata:
- allow CO2 and O2 to diffuse in and out.
- allow water to escape (transpiration).
- close at night to prevent CO2 entering and water escaping and leaf drying out.
- opening and closing of stomata controlled by guard cells.