Human beings are

Options

A. Uricotelic
B. Ureotelic
C. Ammonotelic
D. Both 2 & 3

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the type of excretory product that human beings secrete. This involves knowing the classification of organisms based on their waste products.

2. **Identifying Excretory Products**: There are three main types of excretory products based on nitrogenous waste:
- Ammonotelic: organisms that excrete ammonia.
- Ureotelic: organisms that excrete urea.
- Uricotelic: organisms that excrete uric acid.

3. **Determining Human Excretion**: Humans belong to the category of ureotelic organisms. This means that the primary nitrogenous waste product excreted by humans is urea.

4. **Formation of Urea**: Urea is formed in the liver through the urea cycle. It is less toxic than ammonia, which is why humans excrete it instead of ammonia.

5. **Excretion Process**: After its formation in the liver, urea is transported to the kidneys, where it is filtered out of the blood and excreted from the body through urine.

6. **Evaluating Options**:
- **Uricotelic**: Incorrect, as this refers to organisms that excrete uric acid (e.g., birds).
- **Ureotelic**: Correct, as this refers to organisms that excrete urea (humans).
- **Ammonotelic**: Incorrect, as this refers to organisms that excrete ammonia (e.g., many aquatic animals).

7. **Conclusion**: The correct classification for human beings in terms of excretory products is ureotelic, as they primarily excrete urea.

**Final Answer**: Human beings are ureotelic.

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