Explain how a person could contract variant creutzfeldt-jakob disease by consuming products from a cow with bovine spongiform encephalopathy (mad cow disease).

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 transport tubes for food coming down the plants are called?

Match each term to its best definition? sedimentary depositional enviornment