How is food and energy provided for skin cells

Which is not a characteristic of the animal kingdom? a. they include both vertebrates and invertebrates b. their skin is covered with hair or fur c. they are heterotrophs d. they are eukaryotic

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.

18. how do the cells in meiosis differ from the cells in mitosis?