Comparable segments of the mitochondrial dna sequences of two similar species are shown below. this segment of dna mutates at a rate of one base pair per 33 million years. based on these dna sequences, how long ago did the two species diverge from a common ancestor?

species a mtdna sequence: tacaagatac
species b mtdna sequence: tacgcgtaac

a. 99 million years ago
b. 33 million years ago
c. 66 million years ago
d. 132 million years ago

the overall balanced equation

6co2 + 6h2o > c6h12o6 + 6o2

sunlight energy

where: co2 = carbon dioxide

h2o = water

light energy is required

c6h12o6 = glucose

o2 = oxygen

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.