## **Core Concept**
DNA fingerprinting, also known as DNA typing or genetic fingerprinting, is a method used to identify an individual or trace relationships within a population by comparing samples of their DNA. This technique relies on the unique patterns found in an individual's DNA, which are used to distinguish them from others. The underlying principle is based on the variation and polymorphism in DNA sequences among individuals.

## **Why the Correct Answer is Right**
The correct answer, **C. Alec Jeffreys**, is credited with the invention of DNA fingerprinting in 1984. Jeffreys, a British geneticist, discovered that certain sequences of DNA, known as short tandem repeats (STRs) or microsatellites, are highly variable among individuals. This variability allows for the creation of a unique DNA profile or "fingerprint" for each individual, making it possible to identify people or solve paternity and forensic cases.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While Watson and Crick are famous for describing the structure of DNA, they are not associated with the development of DNA fingerprinting.
- **Option B:** Although Kary Mullis is credited with inventing the polymerase chain reaction (PCR), a technique crucial for amplifying DNA sequences and thus facilitating DNA fingerprinting, he did not discover DNA fingerprinting itself.
- **Option D:** Barbara McClintock was a pioneering geneticist known for her work on transposons and their role in genetics, but she is not associated with the development of DNA fingerprinting.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that DNA fingerprinting is widely used in forensic science to help solve crimes by matching DNA evidence found at crime scenes with DNA samples from suspects or victims. This technique has revolutionized criminal investigations and has also been used in paternity testing and in tracing ancestry.

## **Correct Answer:** C. Alec Jeffreys