What causes gene flow ?

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.

4. how does a phospholipid behave in water? the phosphate head does not mix with water; the fatty acid tails do. the phosphate head and the fatty acid tails mix with water. the phosphate head and the fatty acid tails do not mix with water. the phosphate head mixes with water; the fatty acid tails do not.

Buuy which of the following did you include in your response? organs perform specific functions in the body to keep it alive. organelles perform specific functions in cells to keep them alive. done