One Would Expect to Find the Highest Density of Aquaporins

Question

One would expect to find the highest density of aquaporins in which of the following?
A) the plasma membrane of guard cells
B) the pits of a tracheid
C) the plasma membrane of parenchyma cells in a ripe fruit
D) the plasma membrane of a mature mesophyll cell in a leaf
E) the membrane lining plasmodesmata

Accepted Answer

Aquaporins are proteins that facilitate the transport of water across membranes. Guard cells form stomata in leaves, which are responsible for gas exchange and water regulation. Therefore, having a high density of aquaporins in the plasma membrane of guard cells would facilitate efficient water regulation, making option A the best choice.