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Assertion : The upper surface of the lea...

Assertion : The upper surface of the leaf is darker than the lower surface.
Reason : Spongy mesonphyll contains less chloroplasts than palisade mesophyll cells.

A

If both the assertion and the reason are true and the reason is a correct explanation of the assertion

B

If both the assertion and reason are true but the reason is not a correct explanation of the assertion

C

If the assertion is true but the reason is false

D

If both the assertion and reason are false

Text Solution

Verified by Experts

The correct Answer is:
A
As the upper surface of the leaf is more exposed to the sun than the underside of the leaf there will be more chlorophyll on the upper surface so as to maximize the amount of sunlight that the chlorophyll receives. This results in a more intense green on upper surface then on underside.
Tyloses are outgrowth on parenchyma cells of xylem vessels of secondary heart wood. When the plant is stressed by drought or infection tyloses will fall from the sides of the cells and damp up the vascular tissue to prevent further damage to plant.
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