Most sponges are meaning both sexes occur in the same individual but do not usually self-fertilize because individual sponges produce eggs and sperm at different times.

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.

The probability of producing a normal child by two parents who are carriers for an autosomal recessive disorder is

Anita thinks that she has heterozygous alleles for red hair.if she is correct, which of these diagrams best illustrates anitas alleles pf red hair