Choose the list below that contains the substances required by typical nitrogen-fixing cyanobacteria.

• A. Oxygen, sulfur, light, water, and some minerals
• B. Carbon dioxide, sulfur, light, water, and some minerals
• C. Nitrogen, light, water, and some minerals
• D. Carbon dioxide, ammonium, water, light, and some minerals
• E. Carbon dioxide, nitrogen, water, light, and some minerals

Answer: (E)

Verified step by step guidance

1. Understand the role of nitrogen-fixing cyanobacteria: These organisms are capable of converting atmospheric nitrogen (N₂) into ammonia (NH₃), which can be used to synthesize organic compounds.
2. Identify the basic requirements for photosynthesis: Cyanobacteria, like plants, require light, water, and carbon dioxide (CO₂) to perform photosynthesis, which is essential for their energy production and growth.
3. Recognize the importance of minerals: Minerals are essential for various biochemical processes, including enzyme function and cellular structure maintenance in cyanobacteria.
4. Consider the role of nitrogen: Since cyanobacteria are nitrogen-fixing, they require nitrogen to convert it into a usable form, which is crucial for their survival and function.
5. Combine the elements: The substances required by nitrogen-fixing cyanobacteria include carbon dioxide, nitrogen, water, light, and some minerals, as these support both their photosynthetic and nitrogen-fixing activities.