Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: In recombinant DNA technology, lysozyme is used for disrupting bacterial cells while cellulase is used for plant cells.
Reason R: Isolation of genetic material needs disruption of cells.
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. A is not correct but R is correct
• B. Both A and R are correct and R is the correct explanation of A
• C. Both A and R are correct but R is not the correct explanation of A
• D. A is correct but R is not correct

Hint:

Link assertions and reasons using the word "because". "Lysozyme is used for bacteria and cellulase for plants because isolation of genetic material needs cell disruption." Since this makes logical sense, R is the correct explanation. Memorize the cell wall enzymes: Bacteria \(\rightarrow\) Lysozyme, Plant \(\rightarrow\) Cellulase, Fungi \(\rightarrow\) Chitinase.

Answer 1

The Correct Option is B

Step 1: Understand what the question links together.
The question pairs an Assertion about specific enzymes used to break open cells with a Reason about why we need to break cells at all in recombinant DNA technology.
Step 2: Recall why cells must be broken.
The genetic material (DNA) sits safely inside the cell, hidden behind the cell wall and cell membrane. To get a pure sample of DNA, we first have to disrupt these barriers so the contents spill out.
Step 3: Check Assertion A.
Different cells have different cell walls, so different enzymes are needed. Lysozyme digests the peptidoglycan wall of bacteria, and cellulase digests the cellulose wall of plant cells. So Assertion A is correct.
Step 4: Check Reason R.
Reason R says isolation of genetic material needs disruption of cells. This is exactly the first practical step of DNA isolation, so Reason R is also correct.
Step 5: See if R explains A.
We only bother choosing lysozyme or cellulase because the very purpose is to disrupt the cell and release DNA. So the need for disruption (R) is the reason these wall-digesting enzymes (A) are used. R correctly explains A.
Step 6: Pick the matching option.
Both statements are true and R explains A, which matches option 2.
\[ \boxed{\text{Both A and R are correct and R is the correct explanation of A}} \]