Question

question 8
2 points
the term obligate refers to
a using light for energy production
b existing in a very narrow niche
c using chemicals for energy production
d using oxygen for metabolism
e the ability to exist in a wide range of conditions

Explanation:

In biology, the term "obligate" is used to describe organisms that have a strict requirement for a particular environmental condition or resource. For example, an obligate anaerobe cannot survive in the presence of oxygen, and an obligate parasite must live on or in a host to survive. This means they exist in a very narrow niche. Option A refers to phototrophs (using light for energy - like plants in photosynthesis), C refers to chemotrophs (using chemicals for energy - some bacteria), D could relate to obligate aerobes but is too narrow in context of the general term "obligate" as asked, and E is the opposite (facultative organisms can exist in a wide range, obligate cannot).

Answer:

B. existing in a very narrow niche