Most of the photosynthesis (80%) which takes place on this earth is carried out by

Options

A. green plants on land
B. algae présent in fresh water
C. algae found in ocean
D. algae present in ocean and fresh water sources.

Answer

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy, using carbon dioxide and water to produce glucose and oxygen.

2. **Identifying Major Contributors**: The question asks about the major contributors to photosynthesis on Earth. While green plants are well-known for this process, we need to consider other organisms as well.

3. **Considering Algae**: Algae are significant contributors to photosynthesis, especially in aquatic environments. They can be found in both freshwater and marine ecosystems.

4. **Quantifying Contributions**: It is noted that a large portion of photosynthesis (about 80%) is performed by algae. Specifically, freshwater algae are responsible for a significant amount of carbon dioxide fixation, which is crucial for maintaining oxygen levels in aquatic environments.

5. **Conclusion**: Based on the information, the majority of photosynthesis on Earth (80%) is carried out by algae present in both ocean and freshwater sources.

6. **Final Answer**: Therefore, the correct answer is that most of the photosynthesis (80%) is carried out by algae present in ocean and freshwater sources.

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