Consider the following water conservation mechanism
A. Nasal countercurrent mechanism
B. dependence on metabolic water
C. Highly hypertonic urine
D. Living more on protein rich diet
The kangaroo rat living in desert can survive without drinking water because of

Options

A. A, B & C
B. A, B & D
C. B, C & D
D. A, C & D

Answer

To determine how the kangaroo rat can survive in the desert without drinking water, we need to analyze each of the provided options regarding their role in water conservation.

### Step-by-Step Solution:

1. **Nasal Countercurrent Mechanism (Option A)**:
- The nasal countercurrent mechanism helps to minimize water loss during respiration. In kangaroo rats, the structure of their nasal passages allows for the reabsorption of moisture from exhaled air, which reduces the amount of water lost to the environment. This adaptation is crucial for survival in arid conditions.
- **Hint**: Think about how animals can conserve moisture when breathing in dry environments.

2. **Dependence on Metabolic Water (Option B)**:
- Kangaroo rats rely on metabolic water, which is produced during the oxidation of fats. When fats are metabolized, water is generated as a by-product. This allows them to obtain water internally without needing to drink it.
- **Hint**: Consider how the body can produce water from food sources, especially fats.

3. **Highly Hypertonic Urine (Option C)**:
- The kangaroo rat produces highly concentrated urine, which means that they excrete very little water. This adaptation helps them retain as much water as possible, minimizing water loss through urine.
- **Hint**: Reflect on how urine concentration relates to water retention in organisms.

4. **Living More on Protein-Rich Diet (Option D)**:
- Consuming a protein-rich diet would require more water for the excretion of toxic by-products like ammonia. This would actually lead to increased water loss rather than conservation. Therefore, this option is not a mechanism for survival without drinking water.
- **Hint**: Think about the relationship between diet and water needs for excretion.

### Conclusion:
Based on the analysis of the options:
- The correct mechanisms that allow the kangaroo rat to survive without drinking water are **A (Nasal Countercurrent Mechanism)**, **B (Dependence on Metabolic Water)**, and **C (Highly Hypertonic Urine)**.
- Therefore, the answer is **A, B, and C are correct**.

### Final Answer:
The kangaroo rat can survive without drinking water because of A, B, and C.