Question

Given below are two statements:
Statement (I): Amplified Fragment Length Polymorphism is a type of molecular marker that relies on enzymatic digestion and PCR (Polymerase Chain Reaction).
Statement (II): Restriction Fragment Length Polymorphism is a type of molecular marker that detects variations in the length of DNA fragments generated by digestion with restriction enzymes.
In light of the above statements, choose the most appropriate answer from the options given below.

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

Hint:

Remember:
- RFLP: No PCR, requires high DNA quantity, detected by hybridization.
- AFLP: Combines restriction digestion with PCR amplification, yielding highly reproducible multi-locus profiles.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Molecular markers are used to identify genetic polymorphisms.
AFLP and RFLP are classic DNA profiling techniques that detect restriction site variations across genomes.

Step 2: Detailed Explanation:
Let us analyze both statements:
- Statement (I): Amplified Fragment Length Polymorphism (AFLP) is a multi-step molecular marker assay.
First, genomic DNA is digested using two different restriction enzymes (typically a rare cutter like MseI and a frequent cutter like EcoRI).
Double-stranded oligonucleotide adaptors are then ligated to the sticky ends.
Finally, a subset of the restriction fragments is selectively amplified via PCR using primers complementary to the adaptor and restriction site sequences.
Thus, AFLP relies on both restriction digestion and PCR, making Statement (I) true.
- Statement (II): Restriction Fragment Length Polymorphism (RFLP) is a hybridization-based marker.
Genomic DNA is digested with a restriction enzyme, and the resulting fragments are separated by size via gel electrophoresis.
They are then transferred to a membrane (Southern blotting) and hybridized with a labeled DNA probe.
Polymorphisms are detected as differences in the size and band patterns of restriction fragments.
Thus, RFLP detects variations in DNA fragment length produced by restriction digestion, making Statement (II) true.
Since both statements are true, Option (A) is correct.

Step 3: Final Answer:
Both Statement (I) and Statement (II) are true.