In an attempt to reduce the population of starfish feeding on clams, fishermen cut into pieces and threw overboard any starfish that they caught. The following season there were more starfish than before. This increase in population was most likely the result of

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.

The body is protected against harmful flu viruses by

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.