Question

Given below are two statements about DNA fingerprinting.
Statement (I): The DNA probe used in DNA fingerprinting is a dsDNA obtained from organisms only.
Statement (II): The DNA probe is labeled with radioisotopes and added to nitrocellulose filter paper.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is incorrect but Statement (II) is correct.
• D. Statement (I) is correct but Statement (II) is incorrect.

Hint:

A probe has to pair with complementary DNA on a membrane, so think about whether it is single or double stranded, and how it is labelled.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
In DNA fingerprinting a labelled single-stranded DNA probe hybridises with matching VNTR fragments blotted on a nitrocellulose membrane.

Step 2: Statement I
A probe must be single stranded to pair with complementary sequences. It is not just a double-stranded DNA taken from organisms. So statement I is incorrect.

Step 3: Statement II
The probe is labelled with a radioactive isotope and added to the nitrocellulose paper. So statement II is correct.

Step 4: Conclusion
I is incorrect and II is correct.

Final Answer:
Statement I is incorrect but statement II is correct. \[ \boxed{\text{(C) }\text{Statement (I) is incorrect but Statement (II) is correct}} \]