Question

The amino acid sequences in cytochrome c were determined for chickens, ducks, and humans. Scientists found a difference of 3 amino acids between chickens and ducks, but between chickens and humans there were 13 differences. One may conclude that__________
A. chickens are as closely related to humans as they are to ducks.
B.chickens are more closely related to ducks than they are to humans.
C. chickens are more closely related to humans than they are to ducks.
D. None of the above.

Answer 1

Answer:

B.chickens are more closely related to ducks than they are to humans.

Explanation:

Amino acids are coded for by codons.

Codons are sequence of nucleotide bases from mRNA.

mRNA are synthesized using DNA templates.

Therefore, the more similar the amino acid sequence of two organisms, the more genetically related the organisms are.

Chickens and ducks  had amino acid sequence of 3 while chickens and humans had 13. It thus means that chickens and ducks are more related as compared to chickens and humans.

The correct option is B.