What do the salivary glands, the pancreas, and the stomach have in common?

a) they all mechanically break down food.
b) they all are accessory structures of the digestive system.
c) they all in blood production.
d) they all secrete enzymes that break down food.

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Two pea plants with yellow peas are crossed. most of their offspring have yellow peas, but about 25 percent of the offspring have green peas. for pea color, yellow is the dominant trait and green is the recessive trait. what does this tell you about the two parent plants? a. the parent plants have only dominant alleles for pea color. b. the parent plants are heterozygous for pea color. c. pea color follows an incomplete dominance pattern of inheritance. d. the parent plants are homozygous for pea color.