Question

The bacterial gene Cys E and Cys M introduced in sheep are responsible for ________ .

• A. increase of casein in milk.
• B. resistance to viral and coccidial diseases.
• C. xenotransplantation.
• D. increasing formation of keratin protein.

Hint:

These genes help make the amino acid cysteine, which is needed for wool protein.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
Wool is mainly keratin, a protein rich in the sulphur-containing amino acid cysteine.

Step 2: Gene function
Sheep cannot make enough cysteine. The bacterial genes cysE and cysM code for enzymes of the cysteine synthesis pathway.

Step 3: Result
More cysteine allows more keratin to be made, which improves wool growth.

Final Answer:
The genes increase the formation of keratin protein. \[ \boxed{\text{(D) }\text{increasing formation of keratin protein.}} \]