What is the difference between the cell membrane and the cytoplasm

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.

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?

What organ is the first to receive nutrients that have been absorbed from the digestive tract?