Time that is judged according to some other "marker" of time, such as a person's gray hair is
referred to as
A. absolute time.
B. inferences.
C. radiometric dating.
D. relative time.

The first signs of cellular differentiation occur in the blastocyst. why is cellular differentiation important for the development of a fully formed human infant?

Ascientist wants to determine the effect of a new type of gasoline. he fillsone car with normal gasoline and another identical car with the new gasoline. which is the control group? a. the new type of gasolineb. the car with the normal gasolinec. the car with the new gasolinethe amount of gasoline usedd. the amount of gasoline used

Using meiosis, the sporophyte produces spores that are .