SAT Subject Biology Practice Question 205: Answer and Explanation
15. Which of the following describes a possible path of a carbon atom among atmospheric carbon dioxide, the tissues of a consumer, and the tissues of a producer?
Correct Answer: E
A carbon atom in the tissues of a consumer may be broken down via cellular respiration and released into the atmosphere. There, it may be taken up by a producer and converted to glucose through photosynthesis. The producer may subsequently break down the glucose for energy, once again releasing the carbon into the air. Carbon cannot pass directly from the tissues of a consumer to those of a producer.