السؤال 37

What is the job of the waxy cuticle on the outside of a leaf?

To stop gases from entering the leaf at all
To shade the leaf from light that is too bright
To absorb water from rain falling on the leaf
To cut down the amount of water lost by evaporationالإجابة الصحيحة

الشرح

The waxy layer is waterproof, so it seals the broad flat surface against evaporation and keeps the leaf from drying out in the sun. It is not the barrier to gases that students imagine, because gases travel in and out through the pores of the surface rather than through the wax, and it neither shades the leaf nor soaks up rain.

الشرح

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