3. How do scientists know when a mass extinction took place?
A. They find more fossils of plants.
B. They find fossils of animals that died suddenly.
C. They find a sudden disappearance of many fossil species.
D. They find evidence of changes in Earth's atmosphere.

Energy derived from hot rocks and fluids beneath the earth’s surface is

Glucose is broken down in different ways, both in the presence and in the absence of oxygen. using the table for reference, what major products are formed in each reaction set?

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. an incomplete dominance cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. purple offspring result. then, two of the purple offspring are crossed. according to the punnett square for this cross, how many of the offspring from the second cross will have a feather color that results from incomplete dominance? 1 in 4 2 in 4 3 in 4 4 in 4