The body’s natural defense against pathogens includes skin, tears, saliva,

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.

Consider the last statement in the prompt: "people take such environmental factors into account in their choices when deciding where to live." do all people have a choice as to where they live? what factor plays a key role in this decision and may therefore play a large role in determining quality of life?

Afisherman is dragging his boat from the shore out into the ocean. match the following lists of areas he will move over in the correct order. continental rise continental slope continental shelf [tex]1.[/tex] [tex]2.[/tex] [tex]3.[/tex]