Which of the following is NOT a structural characteristic of epithelial tissue? Cells have the ability to regenerate
Cells have an apical and a basal surface
Cells are attached to a basement membrane
Cells are held together by special proteins
Cells are highly vascular

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 of the following is not associated with invasive species?

Which statements best describe the atoms of the gas neon? check all that apply