Answer:
Answer is C.
Explanation:
For A and B, a base substitution affects one of the three bases that comprise a codon, the DNA/RNA unit that corresponds to a particular amino acid. If one base is substituted, one codon and therefore one amino acid will be affected. Codons have built-in redundancy, so even by changing one base, the new codon sometimes still corresponds to the same amino acid. Therefore, a base substitution at most affects one amino acid, and sometimes doesn't affect it all.
Frameshift mutations cause a lot more trouble. These occur when you have a deletion or insertion that changes the number of bases in your gene. As a result, the "frame" of the codons changes (everything shifts one way or the other by the number of bases added/removed). This affects EVERY codon downstream of the mutation, so you can imagine that such a mutation would have a bigger effect the closer to the start of the gene it occurs. This is why C is correct.
<span>rainwater runoff into local streams </span>
Cell theory is one of the foundations of biology. The observation of Robert Hooke,Anton Van Leeuewenhoek,Matthias Schleiden,Theodor Schwann,Rudolf Virchow, and others led to the devolepment of the cell theory.
Yes, crossing over does not occur during mitosis. As mitosis is simply the duplication of cells, there is no gene variation that comes from crossing-over.
