Question

question 8
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, obligate anaerobes cannot survive in the presence of oxygen, and obligate parasites must live on or in a host organism. This means they exist in a very narrow niche. Option A refers to phototrophs (using light for energy - like plants in photosynthesis), Option C refers to chemotrophs (using chemicals for energy), Option D is about aerobic organisms (but not all obligate are just about oxygen - there are obligate anaerobes too which don't use oxygen), Option E is the opposite of what "obligate" implies (obligate implies a narrow range, not a wide range).

Answer:

B. existing in a very narrow niche