The purines are:

adenine and guanine

cytosine and guanine

cytosine and thymine

ribose and deoxyribose

For women, the hormones estrogen and fsh are both necessary for the:

What was the main advantage of living in a tropical rainforest?

Which of the following is NOT an example of a reflex action? quickly withdrawing your hand after touching a hot pan passing food through your digestive tract blinking your eye when a splinter gets into it NextReset

If the same parents have four boys, what is the probability their fifth child will be a girl?

Which statements accurately describe animals? Check all that apply. All animals are prokaryotes. All animals are multicellular. All animal have cells that contain a nucleus and organelles.

Which stage of sleep is particularly important for learning and memory processing?

Early microbial ecologists knew that hydrogen gas is oxidized in soil and that ammonia is oxidized in sewage. How did these scientists determine that microbes are responsible for these ecological reactions? Choose one: A.

If more genes for less arm hair are passed on more frequently after several generations will people have more or less arm hair?

What kind of tissue is the precursor of long bones in the fetal skeleton?

Why are old rocks rare on the ocean floor