Plant, Tissues and Organs

Question 1

Explain how the palisade mesophyll tissue is adapted for efficient photosynthesis.

Answer 1

Explain how the palisade mesophyll tissue is adapted for efficient photosynthesis.

Question 2

Give 3 differences between xylem and phloem vessels.

Answer 2

Xylem cells are dead, phloem cells are living.
Xylem cells have no cell walls at the top and bottom to allow substances to pass through, phloem cells have sieve plates between cells to allow substances to pass through.
Xylem cells have no subcellular structures, phloem cells have a few

Question 2

Explain how and why stomata open in the day and close at night.

Answer 2

In the day, it is light and the guard cells gain water so become turgid, opening the stomata.
This allows carbon dioxide to enter the cell for photosynthesis and oxygen diffuses out.
At night, it is dark, so plants cannot photosynthesise.