6.12 Environmental Factors

Question 1

Describe how leaves are adapted for photosynthesis

Answer 1

● Broad - large SAfor light absorption
● Thin - short diffusion distance for gases, allows light to reach all cells
● Vascular bundles (xylem and phloem) form a network to deliver
water and remove glucose.Also provide support.
● Photosynthetic pigments (e.g. chlorophyll) absorb light

Question 2

Describe how tissues of the leaves are adapted for

photosynthesis and gas exchange

Answer 2

● Palisade mesophyll layer - receives most light so contains greatest
concentration of chloroplasts
● Upper epidermis - transparent, allows light to reach palisade layer
● Spongy mesophyll layer - air spaces increase the rate of diffusion
● Lower epidermis - contains many stomata for gas exchange