Question

The DNA sequence of a portion of gene in a wild-type organism is TTACCATATTCACCC, and the corresponding peptide sequence is Leu-Pro-Tyr-Ser-Pro. The corresponding gene fragment in phenotypic variant of the organism is TTACCATATTCACCC and the peptide sequence is Leu-Pro-Cys-Ser-Pro. This is an example of a ________ mutation (type) resulting in a ________ mutation (effect).

A) base substitution; silent
B) base substitution; missense
C) deletion; missense
D) insertion; nonsense
E) base substitution; nonsense

Answer 1

The mutation in question involves a change in the DNA sequence that leads to a single amino acid substitution in the protein, characterizing it as a base substitution resulting in a missense mutation. Therefore option B is correct.

Step-by-step explanation:

The DNA sequence of a portion of gene in a wild-type organism is TTACCATATTCACCC, and the corresponding peptide sequence is Leu-Pro-Tyr-Ser-Pro. The corresponding gene fragment in phenotypic variant of the organism is TTACCATATTCACCC and the peptide sequence is Leu-Pro-Cys-Ser-Pro. This is an example of a base substitution mutation resulting in a missense mutation. This missense mutation leads to the replacement of one amino acid in the peptide (Tyr to Cys) without altering the rest of the peptide sequence.