Biology 9700 · AS & A Level · Homeostasis in plants

Homeostasis in plants — practice question

Section B. Answer just one question.
(a)[9]

Explain how guard cells bring about the opening of stomata.

(b)[6]

State the changes in the external environment that lead to stomatal opening and closure. Explain why these stomatal responses are necessary.

Worked solution & mark scheme

This 15-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Proton pumps located in guard cell membranes” …

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