Which of the following statements about competition is true?
a. with competition, the use of a mutually needed resource by one individual or group of individuals lowers the availability of the resource for another individual or group.
b. the species that "wins" competition benefits from the competitive interaction.
c. organisms frequently compete for superiority in the food web.
d. interspecific competition refers to competition within a species.

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.

It is believed that europa, one of jupiter’s moons has an ocean beneath its surface. based on how earth’s oceans and atmosphere are believed to have formed, what can be said about europa’s supposed ocean? the arrival of in the early days of europa’s existence could have formed its ocean. it is likely that the water experienced , similar to earth. it is also possible that this water is retained beneath europa’s surface and in its atmosphere due to europa’s .

Name the organs of humanelemintary canal.