Question

Actinomyocin-D was found to be effective in preventing the growth of rapidly dividing tumor cells by blocking DNA replication. Scientists discovered actinomycin-D also caused side effects like hair loss and a decrease in the number of red blood cells. Which statement best explains the reason that actinomycin-D caused the side effects?

A. Actinomyocin-D alters the environment so that hair and red blood cells are killed B. Actinomyocin-D affects all cell division, so healthy cells are also unable to divide C. Actinomyocin-D targets tumor cells, and the side effects are due to the release of chemicals from the tumor cells D. Actinomyocin-D kills the cells that support the hair cells and red blood cells leading to the death of these cells

Answer 1

I'm no expert, but I study biology, hope the following helps! :) If you think my answer is wrong, please do give feedback, we are all here to learn :)

A and C are similar and vague, and should be striked off.
D is incorrect because the question specifies that Actinomyocin-D blocks DNA replication. The blockage of DNA replication does not necessarily mean death for cells.

B is a possibility, since DNA replication is similar in both Tumour cells and normal cells, and so the drug prevents all cells from dividing, even the healthy ones.