According to the principle of competitive exclusion, two species cannot continue to occupy the same ) environmental habitatb) territoryc) ranged) ecological nichee) biome

C ecological niche

Explanation:

An ecological niche in a habitat, describe the interactions between a species, organisms with the other population of its community, in regards to distribution of resources, competition, predation and parasites.

According to the principle of competitive exclusion, two species can not continue to occupy exactly the same ecological niche in a habitat and coexist peacefully. Species with exactly the same niches will have similar needs and will compete for exactly the same limited resources such as food.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."