1:2:6 Leaf structure

Question 1

What three things adapt for gas exchange?

Answer 1

• Spongy mesophyll cells- have few chloroplasts, large surface area for gas exchange.
• Intercellular spaces- allow diffusion of gases through the leaf.
• Guard cells and stomata- Control the opening and closing of stomata pores, allows gases to diffuse in and out of leaf.

Question 2

What three things adapt for light absorption?

Answer 2

• Epidermis- has cell wall as a physical defence which is transparent to allow light through. It also lacks chloroplasts (allows light to get to the whole leaf)
• Waxy Cuticle- Physical defence, transparent to allow light in, waterproof to reduce water loss.
• Palisade Mesophyll cells- tightly packed with many chloroplasts to increase photosynthesis.

Question 3

What is glucose used for?

Answer 3

Respiration to provide energy for plants.

Storage: it’s converted into starch and oils for storage.

Useful substances, e.g., cellulose in cell walls, chlorophyll and protein for growth.