What are animals called when their DNA is manipulated to possess and express an extra (foreign) gene?

Transgenic animals

The correct answer is Option (1)- Transgenic animals.

Transgenic animals are animals whose DNA has been genetically manipulated to carry and express an extra (foreign) gene that does not naturally belong to their species. This process involves introducing the foreign gene into the animal's genome using techniques such as recombinant DNA technology or genetic engineering.

The foreign gene introduced into the animal's DNA can come from another species or may be a synthetic gene created in the laboratory. Once integrated into the animal's genome, the foreign gene is capable of being expressed, leading to the production of specific proteins or other products encoded by that gene.

Transgenic animals are essential tools in biomedical research, agriculture, and various other fields. They are used to study gene function, model human diseases, and produce valuable proteins or substances of interest. In agriculture, transgenic animals may be engineered to exhibit desirable traits, such as increased disease resistance or improved growth characteristics.

On the other hand, hybrid animals (2) are the result of mating between individuals of two different species or subspecies. They are not necessarily genetically manipulated and are the outcome of natural reproductive processes.

"Transversion animals" (3) is not a standard term in genetics or biotechnology and does not refer to a specific type of animal.

Therefore, the correct answer is (1) Transgenic animals.