Question

a scientist thinks that a certain chemical is a mutagen. she exposes plant cells to a large amount of this chemical in the laboratory. which statement best provides evidence that the substance is a mutagen? the cells die within hours of being exposed to the chemical. the cells grow more quickly than those that were not exposed to the chemical. the cells change after being exposed to the chemical, and this change is passed to the next generation of cells. the cells continue to divide at the same rate as before they were exposed to the chemical.

Explanation:

A mutagen is a substance that causes a change in the DNA sequence of an organism. If the change is passed on to the next generation of cells, it indicates that the DNA (the genetic material) has been altered. Cell death (first option) could be due to toxicity, not necessarily mutagenicity. Faster growth (second option) doesn't directly imply a genetic change. Unchanged division rate (fourth option) shows no genetic impact. Only when the change is heritable (passed to next - generation cells) does it strongly suggest that the chemical has caused a genetic mutation (as mutagens act on DNA to cause heritable changes).

Answer:

The cells change after being exposed to the chemical, and this change is passed to the next generation of cells.