Transgenic animals means

Options

A. Genes of the animal are introduced into other animals
B. All the genes are from the same animal
C. These animals are used as vectors
D. Introduction of exogenous DNA into the genome of an animal to create and maintain a stable heritable character.

Answer

### Step-by-Step Solution

1. **Definition of Transgenic Animals**: Transgenic animals are organisms that have had a foreign gene (exogenous DNA) introduced into their genome. This modification allows them to express new traits or produce specific products that are not naturally found in that species.

2. **Understanding the Terms**: The term "transgenic" can be broken down into two parts: "trans" meaning across or different, and "genic" referring to genes. Therefore, transgenic animals have genes that come from different species or sources.

3. **Example of Transgenic Animals**: A well-known example of a transgenic animal is the Rosy cow. This cow has been genetically modified to produce a higher quantity of milk compared to normal cows. The gene responsible for increased milk production was introduced into the cow's genome.

4. **Mechanism of Creation**: The process of creating a transgenic animal involves introducing a specific gene into the animal's genome. This gene is not originally present in the animal, and its introduction results in a stable heritable trait that can be passed on to future generations.

5. **Clarification of Misconceptions**:
- It is incorrect to say that genes from one animal are simply introduced into another animal's genome without modification. Transgenic animals specifically involve the introduction of genes from different species.
- Animals themselves are not used as vectors for gene transfer; instead, smaller vectors like plasmids or viruses are utilized to carry the gene into the target animal's cells.

6. **Conclusion**: The correct definition of transgenic animals is that they are animals that have been genetically modified to contain and express genes from other species, resulting in desirable traits or products.