The renal portal system of vertebrates is significant for

Options

A. Elimination of excess fats by kidneys
B. Removing nitrogenous wastes in kidneys
C. Supplying food to the kidneys
D. Draining blood from the kidney

Answer

To determine the significance of the renal portal system in vertebrates, we will analyze the provided options step by step.

### Step-by-Step Solution:

1. **Understanding the Renal Portal System**:
- The renal portal system is a network of blood vessels that carries blood from the posterior part of the body to the kidneys. It is primarily found in some vertebrates, such as amphibians and reptiles.

2. **Evaluating the Options**:
- **Option 1: Elimination of excess fats by kidneys**:
- This statement is incorrect. The liver is primarily responsible for the metabolism and elimination of excess fats, not the kidneys.

- **Option 2: Removing Nitrogenous Waste in Kidneys**:
- This statement is correct. The renal portal system plays a crucial role in transporting nitrogenous wastes (like urea) from the blood to the kidneys, where they can be excreted.

- **Option 3: Supplying Food to Kidneys**:
- This statement is incorrect. The renal portal system does not supply food; it primarily transports blood containing waste products to the kidneys.

- **Option 4: Draining blood from the kidney**:
- This statement is also incorrect. The renal veins are responsible for draining blood from the kidneys, not the renal portal system.

3. **Conclusion**:
- After evaluating all options, the correct answer is **Option 2: Removing Nitrogenous Waste in Kidneys**. This highlights the significance of the renal portal system in facilitating the excretion of waste products.