Is it mutualism, commensalism, or parasitism

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.

When explaining dominant and recessive traits to a younger family member, they respond, "well chances are i can probably taste ptc, since dominant traits are more common." how might you address this misconception?

Blood has traveled from the heart to the toes. which describes the next step of the circulation process?