Which two processes result in variations in sexually reproducing species?
(1) mutation and genetic recombination
(2) mitosis and natural selection
(3) extinction and gene replacement
(4) selective breeding and cloning

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.

Do you think the gene eef1 alpha1 supports cell theory? explain your response.

What is it called when part of a cell membrane closes around a molecule to allow the molecule to enter the cell? a. passive transport b.diffusion c. endocytosis d. exocytosisc. endocytosis