Is the ecological role a species plays in a biotic community. -while niche is sometimes used loosely to describe the part of the habitat occupied by a species, this is not the correct biological use of the word. this rules out choices b. and e., while choice c. is clearly wrong. choice d. would be correct if the phrasing were changed from occupied by many related species to occupied by one species. niches do overlap sometimes, but usually organisms occupy different niches, minimizing competition. if two species do occupy the same niche, competition will soon get rid of one of themthis is known as competitive exclusion.