Which molecule is used by cells as an energy source?

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.

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain

Cedric has a low fever and minor aches. yesterday, he went to the doctor for his booster shot and receive the flu shot. which best explains why he has this reaction?