Highlight any four advantages of genetically modified or transgenic animals.

Hint: Genetically modified animals are produced by inserting the gene of interest into the target organism. Animals such as pigs, chicken, cows, fish, mosquitoes are some of the genetically modified animals produced by scientists. In these animals, the embryo is genetically altered by the gene of interest and the resulting animal produces more milk, meat, prevents diseases, etc.

Complete Answer:
The four advantages of genetically modified or transgenic animals are:
i. Transgenic animals can be used as a model system to study diseases. They are specially designed to study the role of genes in the development of certain diseases. Moreover, in order to devise a cure for these diseases, the transgenic animals are used as model organisms. For example, transgenic models have been used for studying diseases such as Alzheimer’s and cancer.
ii. Transgenic animals are useful in the production of vaccines. They are used as model organisms for testing the safety of vaccines before they are injected into humans.
iii. Transgenic animals have been useful in developing various useful biological products. Biological products can be created by the introduction of the portion of DNA or genes that code for a particular product such as human protein (alpha-1-antitrypsin) which is used to treat emphysema.
Iv. In transgenic animals, a foreign gene is introduced. It leads to an alteration of the growth factor. Hence, these animals facilitate the study of gene regulation and their effect on the everyday functions of the body.

Note: It is to be noted that Rudolf Jaenisch in 1974 created a transgenic mouse. He introduced foreign DNA into its embryo, and hence the world's first transgenic animal.