Biologists can divide living organisms into two groups: autotrophs and heterotrophs, which differ in _________.

• A. Their method of obtaining energy.
• B. The characteristics of life.
• C. Their mode of inheritance.
• D. The way that they generate ATP.

Answer: (A)

Verified step by step guidance

1. Understand the definitions: Autotrophs are organisms that can produce their own food from inorganic substances, typically through photosynthesis or chemosynthesis. Heterotrophs, on the other hand, obtain their energy by consuming other organisms.
2. Identify the key difference: The primary distinction between autotrophs and heterotrophs is how they obtain energy. Autotrophs convert light or chemical energy into food, while heterotrophs rely on consuming organic matter.
3. Consider the options: Evaluate each option in the context of the definitions. 'Their method of obtaining energy' directly relates to the difference between autotrophs and heterotrophs.
4. Analyze the other options: 'The characteristics of life' and 'Their mode of inheritance' are general biological concepts that do not specifically address the energy acquisition methods of these groups.
5. Conclude with the correct choice: Based on the analysis, the correct answer is 'Their method of obtaining energy,' as it directly addresses the fundamental difference between autotrophs and heterotrophs.