Photoautotrophs use a. light as an energy source and CO2 as a carbon source. b. light as an energy source and methane as a carbon source. c. N2 as an energy source and CO2 as a carbon source. d. CO2 as both an energy source and a carbon source.

Verified step by step guidance

1. Identify the key terms in the question: Photoautotrophs, energy source, and carbon source.
2. Understand what photoautotrophs are: organisms that use light as an energy source and can convert inorganic carbon (CO2) into organic compounds.
3. Analyze each option: a. light as an energy source and CO2 as a carbon source aligns with the definition of photoautotrophs.
4. Eliminate the incorrect options: b. uses methane, not CO2; c. uses N2, not light; d. incorrectly suggests CO2 as an energy source.
5. Conclude that the correct answer is: a. light as an energy source and CO2 as a carbon source.

Key Concepts

Photoautotrophy

Photoautotrophy is a process by which organisms, such as plants and certain bacteria, convert light energy into chemical energy through photosynthesis. These organisms utilize sunlight to drive the synthesis of organic compounds from carbon dioxide, making them essential for energy flow in ecosystems.

Carbon Sources

In biological systems, carbon sources refer to the materials that organisms use to obtain carbon for growth and metabolism. Photoautotrophs specifically use carbon dioxide (CO2) as their primary carbon source, which is fixed during photosynthesis to produce glucose and other organic molecules.

Energy Sources in Metabolism

Energy sources in metabolism are the means by which organisms obtain energy to fuel their biological processes. For photoautotrophs, light serves as the energy source, enabling them to convert CO2 into organic compounds, while other organisms may rely on different energy sources such as organic compounds or inorganic substances.