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Question 45

What is the job of the upper epidermis in a leaf?

  1. It makes most of the sugar in the leaf, because it faces the sun
  2. It shields the tissue underneath from damage and drying, without blocking lightCorrect answer
  3. It holds the air spaces that gases travel through
  4. It absorbs the carbon dioxide the leaf needs straight through the waxy layer covering it

Explanation

The layer covering the top of a leaf is a single sheet of cells whose job is to keep the working tissue beneath it safe from damage and from drying out, and it does that without costing the leaf its light. It is not where sugar is made, since those cells hold no chloroplasts and a sunlit position cannot make up for that; the air spaces lie further down in the leaf; and carbon dioxide reaches the inside through the pores of the surface, not through the wax on top of it.

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Question 45: What is the job of the upper epidermis in a leaf? · Plants and Photosynthesis · Questena