Maximum number of existing transgenic animals is

Options

A. Mice
B. Cow
C. Pig
D. Fish

Explanation

To determine the maximum number of existing transgenic animals, we can follow these steps:

1. **Understand Transgenic Animals**: Transgenic animals are those that have had a foreign gene deliberately inserted into their genome. This process is often used in research to study gene function and to produce proteins for medical use.

2. **Identify Commonly Used Species**: Various species can be used as transgenic animals, but some are more commonly used than others. Common examples include mice, rats, rabbits, pigs, and cows.

3. **Focus on Mice**: Among these species, mice are the most widely used in transgenic experiments. This is due to several factors:
- Mice have a short reproductive cycle, allowing for quick generation of offspring.
- They are small and easy to handle in laboratory settings.
- Their genetic, metabolic, and physiological processes are similar to those of humans, making them an excellent model for studying human diseases.

4. **Conclusion**: Given that most transgenic experiments are conducted using mice, it can be concluded that the maximum number of existing transgenic animals is found in this species.

5. **Final Answer**: Therefore, the answer to the question is that the maximum number of existing transgenic animals is **Mice**.