Question

which statement best describes how an external factor can produce a genetic mutation?
a. ultraviolet light causes a change to a nucleotide base that is copied when dna replicates.
b. bacteria in polluted water rearranges nucleotide base pairs within dna to produce new traits in a population.
c. solar radiation changes the dna of an individual, resulting in the following generation becoming a new species.
d. strong chemicals penetrate cell membranes and dissolve nucleotide bases within the dna, resulting in a new type of cell.

Explanation:

Ultraviolet light is a mutagen. It can cause changes to nucleotide bases in DNA. When DNA replicates, these changes can be copied. Bacteria rearranging DNA is not a typical way external factors cause mutations in general organisms. Solar radiation changing DNA usually doesn't directly result in a new species in the next - generation in a single step. Strong chemicals dissolving nucleotide bases is not the typical mechanism of genetic mutation as described.

Answer:

A. Ultraviolet light causes a change to a nucleotide base that is copied when DNA replicates.