Question

Read the following four statements (A - D).

(A) The first transgenic cow, Rosie produced milk which was human $\alpha$- lactalbumin enriched.

(B) Restriction enzymes are used in isolation of DNA from other macromolecules.

(C) Downstream processing is one of the steps of R-DNA technology.

(D) Disarmed pathogen vectors are also used in transfer of R-DNA into the host.

Which of the above statement is wrong?

• A. Statements (A) and (C)
• B. Statements (B) only
• C. Statements (B) and (C)
• D. Statements (C) and (D)

Answer 1

The correct option is B Statements (B) only

Restriction enzyme are also called Restriction Endonuclease, a protein produced by bacteria that cleaves DNA at specific sites along the molecule. In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms. Restriction enzymes can be isolated from bacterial cells and used in the laboratory to manipulate DNA fragments, such as those that contain certain specific or desired genes; for this reason they are indispensable tools of recombinant DNA technology/genetic engineering. Isolation of DNA from other macromolecule is achieved by treating the bacterial cells/plant or animal tissue with enzymes such as lysozyme (bacteria), cellulase (plant cells), chitinase (fungus).
So, the correct option is option B.