In an ecosystem, how does photosynthesis by autotrophs most directly benefit heterotrophs?

• A. It converts oxygen into carbon dioxide, providing heterotrophs with a waste gas they must expel.
• B. It produces organic molecules (chemical energy) and releases oxygen that heterotrophs can use for cellular respiration.
• C. It breaks down glucose into ATP, supplying heterotrophs with ATP taken up directly from plants.
• D. It allows heterotrophs to convert light energy directly into glucose in their own cells.

Answer: (B)

Verified step by step guidance

1. Understand the roles of autotrophs and heterotrophs in an ecosystem: autotrophs produce their own food through photosynthesis, while heterotrophs rely on consuming other organisms for energy.
2. Recall the process of photosynthesis, where autotrophs convert light energy into chemical energy by producing organic molecules like glucose and releasing oxygen as a byproduct.
3. Recognize that heterotrophs benefit from photosynthesis because they consume the organic molecules (such as glucose) produced by autotrophs, which serve as their energy source.
4. Note that the oxygen released during photosynthesis is essential for heterotrophs to perform cellular respiration, a process that converts glucose into usable energy (ATP).
5. Conclude that photosynthesis most directly benefits heterotrophs by providing both the organic molecules they consume for energy and the oxygen required for cellular respiration.