This blog will cover and explain the specification for Edexcel triple science course 2013 for biology. Hope it helps :)
Friday, 22 February 2013
2.42 describe the role of stomata in gas exchange
Stomata are minute wholes in the lower epidermis of the leaf. Guard cells regulate the opening and closing of the stomata; allowing carbon dioxide and oxygen to be exchanged between the leaf and the atmosphere. The guard cells absorb water and become turgid- opening the stomata- during the day. At night the guard cells are flaccid and so close the stomata.
Labels:
2.42,
Gas exchange,
Section 2
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