Question

Water molecules cross a plasma membrane of a plant cell due to __________.

A. diffusion
B. aquaporins
C. transport proteins
D. increases in cytoplasmic Ca2+
E. All of the listed responses are correct.

Answer 1

Water molecules cross a plant cell's plasma membrane mainly through aquaporins, which assist in facilitated diffusion, a type of passive transport. So, the correct answer is option b.

Step-by-step explanation:

Water molecules cross a plasma membrane of a plant cell primarily due to aquaporins. Aquaporins facilitate the movement of water through facilitated diffusion, allowing water to move across the cell membrane down its concentration gradient without expending energy.

This process can also be described more broadly as a type of passive transport, but because the question is specifically about water crossing the membrane and aquaporins are specialized for water transport, the correct choice directly related to the process would be B. aquaporins.

So, the correct answer is option b.