Multiple Choice
How do scientists calibrate a molecular clock for a group of organisms with known nucleotide sequences?
A) They use radioactive isotopes to measure the age of DNA material directly.
B) They graph the number of nucleotide differences against the dates of evolutionary branch points known from the fossil record.
C) They analyze fossilized DNA of known age and compare its nucleotide sequences to modern DNA sequences.
Correct Answer:

Verified
Correct Answer:
Verified
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