8
lesson pretestMultiple Choice

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Question 8 • TPS EdX Biology

Which of these cells of the dermal tissue of plants prevent water loss and control gas exchange?

Answer
A
phloem cells
B
companion cells
C
guard cells
D
parenchyma cells

Explanation

Guard cells surround each stoma, a pore in the plant’s outer surface. By opening and closing the stoma, they regulate gas exchange and limit water loss through transpiration. Therefore, the correct choice is guard cells.

AI-written and checked against the verified answer.

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