Which of the following is true feature for transgenic animal

Options

A. Foreign DNA is all its cells
B. Foreign RNA is all its cells
C. Foreign DNA is some of the cells
D. Both 2 and 3

Answer

**Step-by-Step Solution:**

1. **Understanding Transgenic Animals**: Transgenic animals are those that have been genetically modified to contain a gene or genes which have been artificially inserted instead of the animal acquiring them through reproduction. This means they possess foreign DNA in all of their cells.

2. **Identifying Common Transgenic Animals**: While mice are the most commonly used transgenic animals (making up about 95% of all transgenic animals), other species such as rabbits, pigs, sheep, rats, cows, and fish can also be genetically modified.

3. **Analyzing the Options**: The question asks which of the following statements is true regarding transgenic animals. The correct feature of transgenic animals is that they contain foreign DNA in all of their cells.

4. **Eliminating Incorrect Options**:
- **Foreign RNA in all cells**: This option is incorrect because RNA is not a stable genetic material like DNA; it is transient and synthesized as needed.
- **Foreign DNA in some cells**: This option is also incorrect because, in a true transgenic animal, the foreign DNA is integrated into the genome and thus present in all cells derived from the modified cell.

5. **Conclusion**: The true feature of transgenic animals is that they have foreign DNA in all of their cells. This characteristic allows them to be used for various applications, including research, production of biological products, and testing for vaccine and chemical safety.

**Final Answer**: The true feature of transgenic animals is that they have foreign DNA in all of their cells.

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