The amount of matter in an object is known as
the object's weight
the object's size
the object's density
the object's mass

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.

Would really appreciate it, i have an idea but not completely sure

What advantages does a pedigree have over a written passage?