match the excretory products in column I and metabolic reactions during which they are produced in column II and choose the correct option. column I(excretory product) [ a. ammonia, b. Guanines, c. creatinine, d. water] column II (metabolic reaction) [(i) carbohydrate metabolism, (ii) breakdown of creatine phosphate, (iii) protein metabolism, (iv) nucleotides metabolism]

Options

A. a(iii), b(iv), c(ii), d(i)
B. a(iii), b(iv), c(i), d(ii)
C. a(i), b(ii), c(iii), d(iv)
D. a(ii), b(i), c(iv), d(iii)

Answer

To solve the question of matching excretory products with their corresponding metabolic reactions, we will analyze each excretory product from Column I and determine which metabolic reaction from Column II produces it.

### Step-by-Step Solution:

1. **Identify the excretory product: Ammonia (a)**
- Ammonia is produced during the metabolism of proteins. When proteins are broken down, nitrogen is released, resulting in the formation of ammonia as a waste product.
- **Match:** Ammonia (a) → Protein metabolism (iii)

2. **Identify the excretory product: Guanine (b)**
- Guanine is a nitrogenous base found in nucleotides. It is produced during the metabolism of nucleotides, specifically during the breakdown of purines.
- **Match:** Guanine (b) → Nucleotide metabolism (iv)

3. **Identify the excretory product: Creatinine (c)**
- Creatinine is produced from the breakdown of creatine phosphate, which is primarily found in muscle tissue. It is a waste product formed during the metabolism of creatine.
- **Match:** Creatinine (c) → Breakdown of creatine phosphate (ii)

4. **Identify the excretory product: Water (d)**
- Water is produced as a byproduct of carbohydrate metabolism. During processes like glycolysis and the Krebs cycle, water is generated along with energy.
- **Match:** Water (d) → Carbohydrate metabolism (i)

### Final Matches:
- a. Ammonia → (iii) Protein metabolism
- b. Guanine → (iv) Nucleotide metabolism
- c. Creatinine → (ii) Breakdown of creatine phosphate
- d. Water → (i) Carbohydrate metabolism

### Conclusion:
The correct option that matches the excretory products with their respective metabolic reactions is:
- A: (a) → (iii), (b) → (iv), (c) → (ii), (d) → (i)