Which type of DNA is contained in hair?

The correct answer is that hair contains mitochondrial DNA (mtDNA). Mitochondrial DNA is inherited maternally and is found in the mitochondria, the energy-producing organelles within cells. This type of DNA is often used in forensic analysis because it is more abundant in cells compared to nuclear DNA, and hair follicles can provide viable mtDNA even when the hair shaft does not have nuclear DNA.

In forensic contexts, mitochondrial DNA analysis is particularly useful when only a small amount of biological material is available, because it can be recovered from hair that lacks a follicle. Since mtDNA is passed down through the maternal line, it can help link individuals to maternal relatives, making it a valuable tool in cases involving unidentified remains or familial searches.

Other types of DNA mentioned involve different aspects of genetics. Nuclear DNA, for instance, is found in the nucleus of the cell and provides a comprehensive genetic profile but requires follicular material to be recovered from the hair for analysis. Chromosomal DNA and autosomal DNA refer to similar concepts, with autosomal DNA specifically pertaining to non-sex chromosomes. Therefore, for hair analysis where the focus is on the type of DNA prevalent in non-follicular hair, mitochondrial DNA is the most applicable and commonly utilized form.