The best answer to the question above would be the first statement. Cardiorespiratory endurance affects physical fitness in such a way that it increases the efficiency with which the body delivers oxygen and nutrients to its cells.
The two words are Genus and Species.
These sorts of studies can help researchers determine the relative importance of nurture and nature in determining a trait. Nature here would refer to genetics passed down to an individual from its parents, whereas nurture refers to the environment the individual is exposed to.
Mutualism
Explanation: a relationship between two species of organisms in which both benefit from the association.
