Question

When Peter Agre and colleagues compared frog oocytes expressing aquaporin with control oocytes lacking aquaporin placed in pure water, they found that

A) the control oocytes lacking aquaporin swelled and burst as water was transported into the cells.
B) the oocytes expressing aquaporin swelled and burst as water was transported into the cells.
C) the oocytes expressing aquaporin collapsed as water was transported out of the cells.
D) the oocytes expressing aquaporin first swelled and then collapsed as water was transported into and then back out of the cells.
E) the oocytes expressing aquaporin first collapsed and then swelled as water was transported out and then back into the cells

Answer 1

The correct answer is B) the oocytes expressing aquaporin swelled and burst as water was transported into the cells, due to the facilitated movement of water through aquaporin channels following an osmotic gradient.

Step-by-step explanation:

When Peter Agre and colleagues compared frog oocytes expressing aquaporin with control oocytes lacking aquaporin placed in pure water, they found that the oocytes expressing aquaporin swelled and burst as water was transported into the cells. This answer is B) the oocytes expressing aquaporin swelled and burst as water was transported into the cells. Aquaporins are specialized channels in cell membranes that facilitate the transport of water, and when present, they allow water to move rapidly into the cell, following an osmotic gradient.

Without aquaporin, water moves across the phospholipid bilayer at a much slower rate. However, in the presence of aquaporin and a surrounding environment of pure water, the concentration gradient of water between the inside of the cell and the outside causes water to rush into the cell. This influx of water can lead to the cell swelling to the point of bursting, a process similar to hemolysis in red blood cells.