MHT CET Medical202622 April 2026Evening ShiftBiologyMolecular Basis of InheritanceActual
The DNA probe used in DNA fingerprinting consists of ____(A)____ and labeled with ____(B)____. Choose the correct options for (A) and (B) respectively.
Options
- A(A) unknown sequence of double-stranded DNA (B) nitrocellulose filter paper
- B(A) known sequence of double-stranded DNA (B) variable sequences of light and heavy chain
- C(A) unknown sequence of single-stranded DNA (B) sticky and blunt ends
- D(A) known sequence of single-stranded DNA (B) radioactive isotopes
Correct answer
D. (A) known sequence of single-stranded DNA (B) radioactive isotopes
Step-by-step solution
A DNA probe is a small, known sequence of single-stranded DNA or RNA that is complementary to the specific sequence of DNA being sought. It is labeled with a radioactive isotope (or a fluorescent tag) so that it can be easily detected after it hybridizes with its complementary target sequence on the nitrocellulose membrane during DNA fingerprinting. Therefore, (A) is a known sequence of single-stranded DNA and (B) is radioactive isotopes. Answer: (A) known sequence of single-stranded DNA (B) radioactive isotopes