Question 4(c)
[Maximum number: 2]
The diagram shows a transverse section through a leaf.
Explain how layer D is able to regulate gas exchange.
Edexcel IGCSE Biology 2.43B stomata in gas exchange
Practise stomata questions using leaf photographs, surface position, guard cells, gas movement, water loss trade-offs and density estimates.
How this is tested
- explain why stomata position affects CO2 uptake, gas exchange and water loss
- calculate stomatal density or total number from a photograph and leaf area
- describe how guard cells open or close stomata to regulate gas exchange