What is the greatest challenge to organisms that live in a desert biome? a. hot temperatures b. water loss c. sandy soil d. strong winds

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.

Does mitochondria still meet the definition of a eukaryote why or why not?

Which is not a type of symmetry? a. asymmetryb. radial symmetryc. bilateral symmetryd. lateral symmetry