Question

A group of scientists determines that a mitochondrial DNA sequence shared by two species has a constant mutation rate. The sequences of mitochondrial DNA for the two species are shown below.

Species A: GACTGGGCATTA
Species B: GACCGGACATGA

Answer 1

Using the principles of molecular clocks and a known mutation rate for this sequence, the scientists determine that these species diverged from a common ancestor 30 million years ago. Based on this information, how much longer do you predict it would take these species to differ by a total of seven base pairs?

60 million years

20 million years

140 million years

80 million years

Answer 2

@BioEpic

Answer 3

is it 60?

Answer 4

Here is how you do it:
Count how many differences there are in the DNA sequences (there are 3)
Since they diverged 30 MYA, 30/3 is 1 mutation every 10 years.

Answer 5

I would have said 70 years, but there is no option here.
Let me ask @ Praetorian.10

Answer 6

@PRAETORIAN.10

Answer 7

The only possible choice is 140 MYA, if 'differ by a total of seven base pairs' implies that you multiply the answer by 2 (two separate strands).

Answer 8

get it