Will mark brainlist of answer is correct

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.

What is thought to have caused the mass extinction at the end of the cretaceous period?

Earths energy sources include both renewable and nonrenewable resources. name at least three sources of energy that could be used in your house. then describe the ideal energy source for generating most of your homes electricity, and explain why you chose that source. can someone give me some ideas, i’m kinda confused.