AP BIOLOGY

Detailed explanation-1: -A deletion, resulting in a frameshift, results when one or more base pairs are lost from the DNA (see Figure above).

Detailed explanation-2: -Frame-shift mutations occur when a base is added or removed from the sequence. Non-sense mutations create a stop codon, which can prevent the protein from being produced entirely, while missense mutations result in the substitution of one amino acid for another.

Detailed explanation-3: -A frameshift variant occurs when there is an addition or loss of nucleotides that shifts the grouping and changes the code for all downstream amino acids. The resulting protein is usually nonfunctional. Insertions, deletions, and duplications can all be frameshift variants.

Detailed explanation-4: -A frameshift mutation in a gene refers to the insertion or deletion of nucleotide bases in numbers that are not multiples of three. This is important because a cell reads a gene’s code in groups of three bases when making a protein.

Detailed explanation-5: -An insertion mutation occurs when an extra nucleotide is added to the DNA strand during replication. This can happen when the replicating strand “slips, ” or wrinkles, which allows the extra nucleotide to be incorporated (Figure 2). Strand slippage can also lead to deletion mutations.