AP BIOLOGY

Detailed explanation-1: -If a mutation disrupts this normal reading frame, then the entire gene sequence following the mutation will be incorrectly read. This can result in the addition of the wrong amino acids to the protein and/or the creation of a codon that stops the protein from growing longer.

Detailed explanation-2: -A reading frame consists of groups of three nucleotides that each code for one amino acid . 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.

Detailed explanation-3: -So the correct answer is ‘Either an insertion or a deletion of a base’.

Detailed explanation-4: -Frameshift mutations occur when the coding region of a gene is altered by addition or deletion of a number of base pairs that is not a multiple of three. The occurrence of a deletion versus an insertion type of frameshift depends on the nature of the transient intermediate structure formed during DNA synthesis.

Detailed explanation-5: -What may happen when a mutation changes the amino acid sequence of a protein? Messenger RNA may no longer be transcribed because codons change: The protein may become less effective, more effective, or altogether nonfunctional Messenger RNA may identify altered proteins and remove them from the cell.