_is the ability of an organism to change internally or externally in relation to its environment.

Each trait of a plant is determined a. an allele b. one gene c. a pair of genes d. one dominant gene

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.

Name one similarity and one difference between the morphology of a brachiopod and a bivalve