3. Gases pass in and out of a leaf through the
a) stomata
o c) xylem
b) phloem
d) cuticle

a) stomata

Explanation:

The stomata are little pores / doorways / openings that have the express purpose of allowing gases in and out. Without this, plants would not be able to fix carbon, which is essential in respiration.

Why not c or b: The xylem and phloem channel water through the plant, not gases.

Why not d: The cuticle is the waxy outer layer of the leaf meant to protect it, not allow gases through.

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.