A cell biologist examined the DNA content of a cell from a f…

A cell biologist examined the DNA content of a cell from a fruit fly larva during the G1 phase and determined that it had 150 units of DNA. After measuring the DNA content of the same type of cell after the G2 phase, it was discovered that the cell had 300 units of DNA. How is this possible?

Tail length in a certain species of armadillo falls along a…

Tail length in a certain species of armadillo falls along a continuum; a plot of tail length versus frequency displays a normal distribution. Assuming that environmental factors do NOT play an important role in determining tail length, this type of variation probably reflects __________.