Question

What was the amount of alpha-lactalbumin in the milk of a transgenic cow?
A) 2.4 $grams/lit$
B) 4.2 $grams/lit$
C) 3.4 $grams/lit$
D) 4.3 $grams/lit$

Answer 1

Transgenic animals are those animals whose genetic material has been modified either by introducing foreign genes or manipulating its own genetic material. There are many transgenic animals produced like transgenic rats, sheep, cows, fish etc.

Complete step by step answer: Among all transgenic animals, over $95\%$ of them are mice.
In 1997, first transgenic cows were produced called Rosie in which genes responsible for making human protein, alpha-lactalbumin (2.4 $grams/lit$) were introduced. Its milk was rich in human protein which is an important source of bioactive peptides and some essential amino acids like lysine, tryptophan, sulphur-containing amino acids, which is very crucial for infant nutrition and overall development. Transgenic cows contain more alpha-lactalbumin, and also they are more balanced products for human infants than the normal cow milk.
We need transgenic animals for various purposes like:

1. If we want to study how genes are responsible for the functioning of normal physiological processes and the development of organisms.
2. To study genes responsible for particular diseases.
3. Transgenic animals are also made to produce some biological products like a transgenic sheep, which carry the gene, responsible for producing alpha-1-antitrypsin which is used to treat emphysema.
4. Vaccines which are given to humans are first tested on these animals.
5. To test chemical safety, whether a particular drug is safe for humans or not. They are first tested upon transgenic animals.
   Thus, the correct answer is option A.

Note: Many transgenic plants are also produced. They are produced for many purposes like to develop disease-resistant and pest-resistant plants. Examples include Bt cotton: Such cotton is resistant to insects like cotton bollworms.