Question

“A very small sample of tissue or even a drop of blood can help determine paternity.” Provide scientific explanation to substantiate the statement.

Answer 1

The fusion of male and female gametes will give rise to a zygote. The inheritance of character from the mother is called the maternal inheritance. The inheritance of character from the father is called the paternal inheritance. The characters of both mother and father are inherited to the child through genes.

Complete answer:
A paternity test is a test done to determine the father of the child. This test is mainly based on DNA fingerprinting. DNA is present in all cells of human beings. It is present inside the nucleus. The nucleus can be isolated from blood nuclei or the nucleus of the cells. For the isolation of DNA, the nuclear membrane is digested using nuclease enzymes. Later the DNA is isolated from the mixture. The DNA is broken into smaller fragments using restriction enzymes called restriction fragments. The obtained fragments are then separated according to the size using gel electrophoresis. In-gel electrophoresis agarose gel is used as a matrix for the separation. Now the separated fragments are taken and subjected to multiplication using the PCR technique. The DNA is treated with certain chemicals and is made into single bond DNA and the bands are obtained that are called DNA fingerprints.
The DNA of an organism shows the same amount of polymorphism in cells all over the body. The child receives 50 percent of DNA from the father and the rest 50 percent from the mother. DNA fingerprinting a small amount of sample is essential from any part of the body.

Note:
PCR is called a polymerase chain reaction where the function of polymerase i.e. replication is manipulated to obtain multiple copies of a DNA fragment. The instrument used in PCR is called Thermocycler.