An effective vaccine does not exist for the common cold, because

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 spheres are involved when sedimentary rocks formed from parts of seashells at the bottom of the ocean? a.) biosphere, atmosphere, geosphereb.) geosphere, hydrosphere, biosphere c.) geosphere, exosphere, hydrosphered.) hydrosphere, biosphere, atmosphere

Which is not displayed on the graph