Describe one way energy from sunlight moves through a food chain in this food web. identify producers and consumers in the food chain.

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.

Human genes only differ by less than percent. a. 1 b. 6 c. 11 d. 16

Why are human population trends difficult to predict?