Question

Suppose that one virus infects one cell, and 300 minutes later 100 cells are dead (experienced lysis) due to viruses. Which of the following is most likely to describe when lysis occurred for those 100 cells

Lysis occurred for zero cells in the first 150 minutes and for all 100 cells in the last 150 minutes.
Lysis occurred for 30 cells in the first 150 minutes and for 70 cells in the last 150 minutes.
Lysis occurred for 50 cells in the first 150 minutes and for 50 cells in the last 150 minutes.
Lysis occurred for 70 cells in the first 150 minutes and for 30 cells in the last 150 minutes.

Answer 1

Strictly speaking none of these are correct but A is closest. Viruses that lyse cels tend to release relatively large numbers of progeny compared to cells that replicate by splitting into two cells. So two rounds of infection are sufficient to kill all 100 cells. But none of the answers account for the initially infected cell (so A is wrong) or explain how one virus could initially infect many cells (so B, C and D are incorrect).

The accurate description would be "Lysis occurs in 1 cell in the first 150 minutes (releasing 99 progeny) and for 99 cells in the last 150 minutes." to account for two rounds of infection.

Answer 2

Lysis occurred for 30 cells in the first 150 minutes and for 70 cells in the last 150 minutes