Question 1
Multiple choiceEasy1 markFour equal samples of cells lacking cell walls were placed in different media. Their volumes after 5 min are shown as percentages of their initial volumes. Which medium would give the cells the greatest risk of bursting?
| Medium | Cell volume after 5 min (% of initial volume) |
|---|---|
| P | 130 |
| Q | 112 |
| R | 100 |
| S | 88 |
Show answer and explanation
Answer: A. Water entering cells causes them to swell, and cells without cell walls can burst in a hypotonic medium. The greatest increase in volume is in P, at 130% of the initial volume, so this medium gives the greatest risk of bursting.
B: recognizes swelling in Q but overlooks that its volume increase is smaller than in P.
C: treats unchanged volume as swelling; it indicates no net change in cell volume.
D: reverses the direction of water movement: the decrease in volume indicates shrinkage, not swelling.
Remember: water entry swells cells without walls; water loss shrinks them.