Consider the following statements about carbon cycle and choose how many statements are correct?
(a) Atmosphere has 71% of total global carbon
(b) Decomposers contribute substantially to `CO_2` pool by their processing of waste materials and dead organic matter of land or oceans
(c) `4 xx 10^(13)kg` carbon is fixed through photosynthesis annually
(d) No respiration input into atmosphere
(e ) Carbon constitutes 49% of dry wt. of organisms

Options

A. two
B. three
C. four
D. five

Answer

To determine how many statements about the carbon cycle are correct, we will evaluate each statement one by one.

### Step-by-Step Solution:

1. **Evaluate Statement (a)**:
- Statement: "Atmosphere has 71% of total global carbon."
- Analysis: This statement is incorrect. The majority of global carbon (about 71%) is found in the oceans, while only about 1% is found in the atmosphere.
- Conclusion: **Incorrect**

2. **Evaluate Statement (b)**:
- Statement: "Decomposers contribute substantially to `CO_2` pool by their processing of waste materials and dead organic matter of land or oceans."
- Analysis: This statement is correct. Decomposers break down dead organic matter and waste, releasing carbon dioxide back into the atmosphere.
- Conclusion: **Correct**

3. **Evaluate Statement (c)**:
- Statement: "`4 x 10^(13) kg` carbon is fixed through photosynthesis annually."
- Analysis: This statement is also correct. It is estimated that around 4 x 10^13 kg of carbon is fixed through photosynthesis each year.
- Conclusion: **Correct**

4. **Evaluate Statement (d)**:
- Statement: "No respiration input into atmosphere."
- Analysis: This statement is incorrect. Respiration by organisms releases carbon dioxide into the atmosphere, contributing to the carbon cycle.
- Conclusion: **Incorrect**

5. **Evaluate Statement (e)**:
- Statement: "Carbon constitutes 49% of dry weight of organisms."
- Analysis: This statement is correct. Carbon is a major component of biological molecules and constitutes a significant portion of the dry weight of organisms.
- Conclusion: **Correct**

### Summary of Evaluations:
- Statement (a): Incorrect
- Statement (b): Correct
- Statement (c): Correct
- Statement (d): Incorrect
- Statement (e): Correct

### Total Correct Statements:
Out of the five statements, three statements (b, c, and e) are correct.

### Final Answer:
**3 statements are correct.**

---