B4 Functions of the parts of the leaf 0.0 / 5 ? BiologyLeaves and PhotosynthesisGCSEOCR Created by: will.tudorCreated on: 20-02-16 17:50 What does the waxy cuticle do? Restricts water loss from the leaf. 1 of 13 Why is the upper epidermis transparent? To allow sunlight through to the layer below. 2 of 13 Why are the cells in the palisade layer positioned near the top of the leaf? To absorb the maximum amount of light. 3 of 13 Why are the cells in the palisade layer packed with chloroplasts? To absorb the light energy needed for photosynthesis. 4 of 13 What does the spongy mesophyll contain? Lots of air spaces connected to the stomata. 5 of 13 What does this ensure? The optimum exchange of gases. 6 of 13 What does the lower epidermis contain? Most of the stomata. 7 of 13 What do the stomata allow? The diffusion of gases (eg. CO2 & O2) in and out of the leaf. 8 of 13 What do guard cells control the size of and why? The stomata to restrict water loss. 9 of 13 What do vascular bundles contain? Xylem and phloem. 10 of 13 What do these do? Transport water and sugars through the leaf. 11 of 13 Describe the internal surface area-to-volume ratio of leaves Leaves have a large internal surface area-to-volume ratio. 12 of 13 What do this improve? The rate of gaseous exchange between photosynthesising cells and the air spaces. 13 of 13
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