Henle's loops are found in those animals which excrete hypertonic urine. One of the following does not have henle's loop.

Options

A. Birds
B. Mammats
C. Forgs
D. Repities

Answer

**Step-by-Step Solution:**

1. **Understanding Henle's Loops**: Henle's loops are structures found in the nephrons of certain animals that play a crucial role in the concentration of urine. They help in the reabsorption of water and nutrients, allowing animals to excrete hypertonic urine, which is more concentrated than the blood plasma.

2. **Identifying the Animals**: The question provides four options: birds, mammals, frogs, and reptiles. We need to determine which of these does not possess Henle's loops.

3. **Analyzing Each Option**:
- **Birds**: Birds have a small Henle's loop that aids in water reabsorption, which is essential for their survival as aerial animals.
- **Mammals**: Mammals have well-developed Henle's loops that are crucial for concentrating urine and conserving water.
- **Reptiles**: Reptiles also possess Henle's loops, which help them in water reabsorption, especially in arid environments.
- **Frogs**: Frogs, being amphibians, have a very short nephron and do not have Henle's loops. This is because they live in or near water, so they do not need to conserve water as much as the other animals.

4. **Conclusion**: Based on the analysis, the animal that does not have Henle's loops is **frogs**.

**Final Answer**: Frogs do not have Henle's loops.

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