Question

multiple choice 1 point
a red blood cell placed in a beaker of solution immediately begins to swell and ultimately bursts. this occurs because the cytoplasm of the cell was

hypertonic, isotonic
hypotonic, hypertonic
hypotonic isotonic
hypertonic, hypotonic
isotonic hypotonic

Explanation:

To solve this, we recall osmosis concepts: A hypertonic solution has higher solute concentration (lower water) than the cell, a hypotonic solution has lower solute (higher water), and isotonic has equal. When a red blood cell swells and bursts, water enters the cell. This happens when the cell's cytoplasm is hypertonic (higher solute, so water moves in) and the beaker solution is hypotonic (lower solute, so water moves into the hypertonic cell). Wait, no—wait, the cell swells because water moves into it. So the cell's cytoplasm (inside) is hypertonic relative to the beaker's solution (outside, hypotonic). So the cytoplasm was hypertonic, and the beaker solution was hypotonic? Wait, the options: looking at the selected option (the circled one) is "hypertonic; hypotonic". Let's check: If the cell's cytoplasm is hypertonic (more solute, less water) and the beaker solution is hypotonic (less solute, more water), water moves from the hypotonic solution (beaker) into the hypertonic cytoplasm (cell), causing the cell to swell and burst. So the correct option is the one with cytoplasm hypertonic and beaker solution hypotonic, which matches the circled option: hypertonic; hypotonic.

Answer:

The correct option (the circled one) is: hypertonic; hypotonic (the option labeled with the circle, likely the fourth option in the list: "hypertonic; hypotonic").