Why Do Different People Have Different DNA Fingerprints

Question

Why do different people have different DNA fingerprints?
A) They have completely different kinds of VNTRs.
B) They have different numbers of the same VNTR.
C) PCR generates some sequences more than other sequences.
D) Restriction enzymes may not cut some VNTRs next to specific DNA sequences.

Accepted Answer

The DNA fingerprint of an individual is made up of variable number tandem repeats (VNTRs), which are repeated sequences of DNA. Different individuals may have the same VNTR sequences, but they will have different numbers of those sequences. This results in unique DNA fingerprints for each individual. Therefore, choice B is correct. Choice A is incorrect because VNTRs are the same types of sequences in all individuals, but they differ in their number. Choice C is incorrect because PCR amplifies all VNTR sequences equally. Choice D is incorrect because restriction enzymes cut VNTRs based on a specific recognition sequence, and this is the same in all individuals.