An example of a polygenic trait is human skin color variation. Several genes factor into determining a person's natural skin color, so modifying only one of those genes can change skin color slightly or in some cases, such as for SLC24A5, moderately.
Case 1 â The Alleged Father has Recently Passed Away. If less than a week has passed since the deceased died, then if permission can be obtained, fingernail cuttings and a hair sample with root attached can be used to extract DNA samples to establish paternity. It is a more complex procedure than a buccal swab, but the DNA matching is just as accurate.
Only a small sample of cells is needed for DNA fingerprinting. A drop of blood or the root of a hair contains enough DNA for testing. Semen, hair, or skin scrapings are often used in criminal investigations.A person who has DNA fingerprinting done voluntarily usually provides a sample of blood taken from a vein.hy It Is Done. DNA fingerprinting is done to: 1  Find out who a person's parents or siblings are. 2  This test also may be used to identify the parents of babies who were switched at birth. 3  Solve crimes (forensic science).