Answer:

DNA fingerprinting

is the correct answer

Answer:

The real father could be identified by the method of DNA fingerprinting.

Explanation:

DNA Fingerprinting:

➣The sequence of DNA of each human being is 99.9 percent similar. It is the 0.1 percent difference which makes every individual unique.

➣ DNA fingerprinting involves identifying these differences in the repetitive DNA regions of the DNA sequence. Here a small stretch of DNA is repeated multiple times.

➣ By density gradient centrifugation, the repetitive DNA is separated from the bulk DNA. The major peak is formed by the bulk DNA and satellite DNA forms the small peaks.

➣ The satellite do not co de for any protein but has a high degree of polymorphism and form a large portion of the human genome and hence forms the basis of DNA fingerprinting.

➣ DNA is taken from tissues such as saliva, blood, hair follicle, sperm, bone, skin etc for DNA fingerprinting.

➣ This method was initially developed by Alec Jeffreys who used a satellite DNA (VNTR) as a probe which showed high degree of polymorphism.

Steps involved in DNA fingerprinting:

1. DNA isolation

2. DNA is digested by molecular scissors such as restriction endonucleases.

3. By gel electrophoresis, the DNA fragments are separated.

4. The separated DNA fragments is transferred to a synthetic membrane such as nylon or nitrocellulose.

5. By using a labelled VNTR (Variable Number of Tandem Repeats), DNA is hybridised.

6. The hybridised DNA fragments is detected by autoradiography which give bands of different sizes.

7. For an individual DNA, these bands give a characteristic pattern and differ from individual to individual.