Transgenic rats, rabbits, pigs, sheep,. Cows and fish have been produced, Almost over 95 per cent f all existing transgenic animals are :

Options

A. sheep
B. fish
C. mice
D. pigs

Answer

**Step-by-step Solution:**

1. **Understanding Transgenic Animals**:
- Transgenic animals are those whose genomes have been altered by the transfer of one or more genes from another species or breed. This genetic modification allows for the study of gene function and the development of new traits.

2. **Identifying the Majority of Transgenic Animals**:
- While various species such as rats, rabbits, pigs, sheep, cows, and fish have been produced as transgenic animals, the question asks for the majority of these animals.

3. **Researching Existing Data**:
- According to existing data, it is noted that over 95% of all existing transgenic animals are mice. This indicates that mice are the most commonly used transgenic animals in research and biotechnology.

4. **Evaluating the Options**:
- The options provided include sheep, fish, and mice. Based on the information gathered, mice are the correct answer since they constitute the majority of transgenic animals.

5. **Conclusion**:
- Therefore, the correct answer to the question is that 95% of all existing transgenic animals are mice.

**Final Answer**: Mice

---