Question

Why is crossing over important to Forensic Biology?

Why is independent assortment important in Forensic Biology?

Answer 1

Crossing over is a phenomenon in which chroomosomal segments between the non-sister chromatids during the production of gametes. This means the offspring will carry a combination of the chromosomes from either parental side, which would now be different from the parental chromosomes.

This is used in forensic biology as a fact for example, making a DNA match between victim (died) of a crime, to the parental DNA to confirm whether the victim is actually biologically related to the parents.

Independent assortment is a law stated by mendel that during gamete formation the alleles of different genes are assorted independently to the offsprings, to produce a variety of combination of traits in the offsprings.

This is related to the Short Tandem Repeats (STRs) occuring in DNA that are used in the forensic sciences. These are the repeats (highly conserved) that are relatively easy for measuring and can be compared between different individuals. There are several government databases for STR loci employed in the identification of the individuals. These STRs are inherited from the parents in a combination which decide the phenotype of the individual. Hence we can match the STRs of the DNA samples that are taken from the crime site, to that with the database to find the prime suspects.