Question

question 7 of 25
how do animals get the nitrogen they need?

a. through cellular respiration

b. by eating plants

c. by breathing

d. through photosynthesis

Explanation:

• Option A: Cellular respiration is for energy production (using glucose and oxygen, producing CO₂, water, and ATP), not for obtaining nitrogen.
• Option B: Plants absorb nitrogen (e.g., as nitrates from soil) and incorporate it into organic compounds. Animals eat plants (or other animals that ate plants) to get nitrogen - containing organic matter (like proteins, nucleic acids) which provides the nitrogen they need.
• Option C: Breathing takes in oxygen and releases carbon dioxide; nitrogen in the air is not absorbed in a way that provides the nitrogen animals need for biological processes.
• Option D: Photosynthesis is a process by plants (and some others) to make glucose using light energy, carbon dioxide, and water; animals don't perform photosynthesis.

Answer:

B. By eating plants