Which of the following is NOT among the seven basic life functions?

• A. Ingestion
• B. Photosynthesis
• C. Excretion
• D. Respiration

Answer: (B)

The idea being tested is which activities are considered universal life processes that all living things perform to stay alive. Ingestion, excretion, and respiration are classic examples of these fundamental tasks: taking in food, removing wastes, and releasing energy from nutrients. Photosynthesis, on the other hand, is a specific energy-making process used by plants and some microscopic organisms to convert light into chemical energy. It isn’t a universal life function because many organisms, like animals, don’t photosynthesize and must obtain energy by consuming other organisms. So photosynthesis isn’t among the seven basic life functions, which is why it’s the correct choice.