Stem cells have the ability to divide

Which would prevent a plant from growing? oa. lack of sunlightob. no supply of lithiumoc. too much waterd. too many monosaccharides

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.

Match the types of competition to their descriptions