Which element of weather is caused by a difference in air pressure between two air masses?

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.

Which of these best describes what occurs during cytokinesis? a) the chromosomes are separated b) the cell begins to divide by replicating the chromosomes c) the cytoplasm is divided between the two new daughter cells d) the nucleus opens to allow the chromosomes to enter the cytoplasm

What are the three types of counseling established by marine corps policy?