Question

In which of the following molecular markers, polymerase chain reaction (PCR) is required?
A. Restriction Fragment Length Polymorphism (RFLP)
B. Random Amplified Polymorphic DNAs (RAPD)
C. Amplified Fragment Length Polymorphism (AFLP)
D. Sequence-Tagged Sites (STSs)
Choose the correct answer from the options given below:

• A. A, B and C only
• B. A, C and D only
• C. A, B, C, D
• D. B, C and D only

Hint:

A quick way to solve this is to look for the word "Amplified" in the name of the marker (like in RAPD and AFLP), which is a direct giveaway that PCR is involved. For others, remember that RFLP is the classic, non-PCR hybridization-based method.

Answer 1

The Correct Option is D

Step 1: Concept Overview:
The question requires identifying molecular marker techniques that utilize Polymerase Chain Reaction (PCR) as a fundamental component. PCR amplifies specific DNA segments.
Step 2: Detailed Analysis:
Evaluating each marker technique:

A. Restriction Fragment Length Polymorphism (RFLP): This is a PCR-independent method. It involves restriction enzyme digestion of genomic DNA, fragment separation via gel electrophoresis, and detection of specific fragments using labeled probes in Southern blotting. It does not involve an amplification step.

B. Random Amplified Polymorphic DNAs (RAPD): As the name indicates, this technique uses short, arbitrary primers to amplify random genomic DNA segments via PCR. Polymorphism is indicated by the presence or absence of amplified bands. PCR is crucial.

C. Amplified Fragment Length Polymorphism (AFLP): This technique also incorporates "Amplified" in its name. The process begins with restriction digestion, followed by adapter ligation and selective PCR amplification of fragment subsets. PCR is crucial.

D. Sequence-Tagged Sites (STSs): An STS is a short, unique genomic sequence detected by designing specific PCR primers. Successful amplification confirms STS presence. PCR is crucial.

Step 3: Conclusion:
RAPD, AFLP, and STS rely on PCR, while RFLP does not. Therefore, the correct answer is B, C, and D.