Question

A geneticist was able to reconstruct a sequence of mitochondrial DNA of a prehistoric insect that was encased in amber. A segment of this DNA was found to have the sequence AGGTCCTAAG. This segment of DNA has had a single mutation every 100 million years. The following sequences have mutated from the original prehistoric sequence, as shown by the highlighted substituted nucleotides. Which of these sequences most likely belongs to this insect's descendant after 200 million years have passed?

A. AGATCTCGGA
B. AAGTTTTAAA
C. AGGCCCCAAG
D. AAGTTTCAGG

Answer 1

AGGCCCCAAG

Step-by-step explanation:

Only two letter changed, which means it is the closest to the original sequence.

Answer 2

C. AGGCCCCAAG is the answer because only two letters changed from the original DNA strand AGGTCCTAAG. The bolded letters show changed letters in the DNA, and the unbolded letters did not change in the 200 million years.