Question

the diagram below shows a cross section of a plant leaf.
cross section of a plant leaf
cuticle upper
epidermis
palisade
layer
mesophyll
layer lower
epidermis
guard cell x
how does the structure marked x contribute to the survival of the plant?
a. it allows the intake of gases necessary for photosynthesis.
b. it allows the intake of minerals necessary for plant growth.
c. it allows the intake of sunlight necessary for atp production.
d. it allows the intake of sugars necessary for plant reproduction.

Explanation:

Structure X is a stoma (formed by guard cells), which is the pore for gas exchange. Photosynthesis needs \( \text{CO}_2 \) (intaken via stomata) and releases \( \text{O}_2 \). Minerals are absorbed by roots (B is wrong), sunlight is captured by chloroplasts (C is wrong), and sugars are produced by the plant, not taken in (D is wrong). So A is correct.

Answer:

A. It allows the intake of gases necessary for photosynthesis.