Question 6
(Multiple Choice)
A mutant yeast strain stops proliferating when shifted from 25°C to 37°C.When these cells are analyzed at the two different temperatures, using a machine that sorts cells according to the amount of DNA they contain, the graphs in Figure 18-2 are obtained. 
Figure 18-2
Which of the following would NOT explain the results with the mutant?
A)inability to initiate DNA replication
B)inability to begin M phase
C)inability to activate proteins needed to enter S phase
D)inappropriate production of a signal that causes the cells to remain in G1
Answer