Which statement regarding genes and evolution is true?
A. If an organism has a mutation, it will be less "fit" (less able to reproduce) than other organisms.
B. Today's plethora of microorganisms is the result of an extremely brief period of genetic recombination events.
C. Mutations function to prevent the offspring of an organism from evolving.
D. Random, heritable genetic mutations are a source of genetic variation. This variation is necessary for natural selection to occur.

c. movement because i took the test and it lets me review my answers

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.