Answer:
A new mutation
Explanation:
A mutation refers to the random changes in the DNA of organisms. A mutation changes the allele and genotype frequencies by the introduction of a new allele in the gene pool.
However, mutations are not the major factor responsible for changes in the gene pool of a population as mutations are rare. The rate of mutations is very slow and does not allow it to serve as a major factor to change the allele and genotype frequencies.
The most true answer from these choices is:
Methyl groups most often added to guanine-cytosine base pairs because they are held by three hydrogen bonds, and this decreases the probability of gene expression.
<span>Proteins are different based on number and type of ____________ contained in their polypeptide chain(s)
</span>Amino acids
