Homologous structures are body parts of organisms that are similar in structure and position but have different function. Which set of organism
structures are homologous?

a. wing of a bat; wing of a bee

b. flipper of a porpoise; foreleg of an elephant

c. flipper of a whale; leg of a centipede

d. leg of a spider, leg of a frog

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 body is protected against harmful flu viruses by

Creation of an unnaturally uniform sample to represent a diverse populationcan be avoided by: a. including only willing b. asking another scientist for .c. choosing only identical participants.d. selecting individuals at random.