Which of the following set of animals have testes located permanently in abdomen ?

Options

A. Bat , rat , rabbit , otter , lama
B. Dolphin , sloth , armadillo , hedge hog
C. Whales , elephants , monotremes , seals
D. Both 2 and 3

Answer

To determine which set of animals have testes located permanently in the abdomen, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Function of Testes**:
- Testes are responsible for the production of sperm. For optimal sperm production, they need to be at a temperature slightly lower than the normal body temperature.

2. **Identify Animals with Abdominal Testes**:
- Some animals have adapted to have their testes located in the abdomen. This is often due to their internal body temperature being suitable for spermatogenesis.

3. **List of Animals with Abdominal Testes**:
- The animals known to have their testes permanently located in the abdomen include:
- Dolphin
- Sloth
- Armadillo
- Hedgehog
- Whale
- Elephant
- Monotremes (like platypus)
- Seals

4. **Contrast with Animals with External Testes**:
- In contrast, animals like bats, rats, rabbits, turtles, and llamas have their testes located outside the body in a scrotum.

5. **Conclusion**:
- Based on the information, the correct answer to the question is the set of animals that includes Dolphin, Sloth, Armadillo, Hedgehog, Whale, Elephant, Monotremes, and Seals, as they have testes located permanently in the abdomen.