Question

Oxygen is not produced during photosynthesis by

• A. Green sulphur bacteria
• B. Cycas
• C. Nostoc
• D. Chara

Answer 1

The Correct Option is A

The question asks which of the given organisms does not produce oxygen during photosynthesis. To answer this question, we need to understand the process of photosynthesis and how it varies among different groups of organisms. Let's analyze each option one by one:

1. Green Sulphur Bacteria: These bacteria perform a type of photosynthesis that does not produce oxygen. They use hydrogen sulfide (H₂S) instead of water as an electron donor, resulting in the production of sulfur instead of oxygen. This process is called anoxygenic photosynthesis.
2. Cycas: Cycas is a genus of seed plants. Similar to most land plants, Cycas performs oxygenic photosynthesis, where water is used as an electron donor, and oxygen is released as a byproduct.
3. Nostoc: Nostoc is a genus of cyanobacteria. Cyanobacteria are known for carrying out oxygenic photosynthesis, where oxygen is produced as a byproduct.
4. Chara: Chara is a genus of green algae. Like other green plants, Chara also performs oxygenic photosynthesis, releasing oxygen.

Based on the above explanation, the correct answer is that oxygen is not produced during photosynthesis by green sulphur bacteria. The other listed organisms, including Cycas, Nostoc, and Chara, perform oxygenic photosynthesis, which results in the production of oxygen.