Question

A mutation results in a base substitution of the c/g base pair at position 22 with a/t base pair. What is the result of this mutation?

1) No change in the amino acid sequence
2) A different amino acid is incorporated into the protein
3) The protein is not synthesized
4) The protein is synthesized but does not function properly

Answer 1

Option 1: A base substitution mutation could lead to a silent mutation with no change in the amino acid sequence, a missense mutation changing the amino acid incorporated.

Step-by-step explanation:

A base substitution mutation where a c/g base pair is replaced with an a/t base pair could have different outcomes depending on the context of the mutation within the gene. If the mutation occurs in a region where the base change does not alter the amino acid, due to the redundancy in the genetic code, it is known as a silent mutation and would not change the amino acid sequence (option 1).

However, if the substitution alters the amino acid that is incorporated into the protein, this is called a missense mutation (option 2), which can potentially result in a protein with altered function. There is also the possibility of a nonsense mutation, if the substitution converts an amino acid codon into a stop codon, potentially leading to a truncated, nonfunctional protein (option 3). Lastly, if the protein can still be synthesized but does not function properly due to the mutation, this would fit option 4.