Leaf Structure

Question 1

What is important about the upper epidermis

Answer 1

The upper epidermis is one cell thick and covers the leaf like skin. The cuticle is a waxy layer which orotects the leaf against disease organisms such as parasitic fungi

Question 2

What is important about the palisade cells

Answer 2

Palisade cells have a cylindrical shape. This helps the light to penetrate into the leaf. Chlorophyll is contained in chloroplasts. Palisade cells have more chloroplasts than other cells in the leaf. The chloroplasts can move within the cell to regions where light intensity is greatest

Question 3

What is important about the Palisade mesophyll layer

Answer 3

This layer consist of irregular shaped cells with large air spaces between them and looks like a sponge when seen under a microscope. The cells have fewer chloroplasts than the palisade cells since the light intensity is less

Question 4

What is important about the lower epidermis

Answer 4

The lower epidermis is a layer one cell thick, like the upper epidermis. It contains pores called stomata. Each stoma is made up of a pair of guard cells. The stoma allow gases and water vapour to diffuse in and out of the leaf

Question 5

What is important about the guard cells

Answer 5

Stomata open and close in response to changing conditions, such as light intensity, humidity and carbon dioxide concentration

Question 6

What is important about the leaf vein including the xylem and phloem vessels

Answer 6

Water and salts enter the leaf via the xylem. Sugar made by photosynthesis passes out of the leaf via the phloem