Question

Which of the following is related to the heterotroph hypothesis?

• A. Anaerobic and aerobic organisms evolved simultaneously
• B. Photosynthetic autotrophs evolved first since they required only energy from the sun and simple molecules from the environment
• C. Autotrophs evolved before a carbon source was made available
• D. Anaerobic heterotrophs evolved first
• E. Chemosynthesis was critical to the evolution of heterotrophic organisms

Answer 1

Answer: (D)

Anaerobic heterotrophs evolved first

Heterotrophs are organisms that obtain their food from other organisms as they cannot produce their own food. In food chains, they are usually secondary or tertiary consumers. The heterotroph hypothesis states that the first living organism was a heterotroph.It also assumed that the anaerobic heterotrophs evolved first.

So, the correct answer is 'Anaerobic heterotrophs evolved first'.