Question

question 16
of the items listed, which is not required for the maintenance of life?
a food
b carbon dioxide
c pressure
d water

Explanation:

Food provides energy and nutrients. Water is essential for many biological processes. Pressure (like atmospheric pressure) is important for functions like gas exchange. Carbon dioxide is mainly used by plants for photosynthesis. Animals do not require it for basic life - maintenance (they produce it as a waste product).

Answer:

B. carbon dioxide