AP BIOLOGY

THE CELL

TRANSPORT INTO AND OUT OF THE CELL

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
In pure water, a red blood cell from an animal will swell and burst, but a leaf cell from a plant will not. Which structure in the leaf cell is responsible for this difference?
A
cell membrane
B
cell wall
C
mitochondrion
D
nucleus
Explanation: 

Detailed explanation-1: -Plant cells swell up when kept in hypotonic solution because plant cells absorb large amounts of water in hypotonic solution such that the vacuole is completely filled with water and the cytoplasm presses against the cell wall. But it does not get burst due to the presence of cell wall.

Detailed explanation-2: -Red blood cells placed in a solution with a higher water concentration compared to their contents (eg pure water) will gain water by osmosis, swell up and burst. Water will diffuse from a higher water concentration outside the cell to a lower water concentration inside the cell.

Detailed explanation-3: -So, the correct answer is ‘Cells wall is rigid and does not get overstretched’

Detailed explanation-4: -A red blood cell will swell and undergo hemolysis (burst) when placed in a hypotonic solution. When placed in a hypertonic solution, a red blood cell will lose water and undergo crenation (shrivel).

Detailed explanation-5: -Whenever there is a low concentration of nonpenetrating solute and a high concentration of water outside relative to inside, the environment is hypotonic. Water will move into the cell, causing it to swell. In animal cells, the swelling ultimately causes cells to burst and die.

There is 1 question to complete.