Distinguishing features of nuclear and mitochondrial DNA (Answer in 150 words)

- Distinguishing features of nuclear and mitochondrial DNA (Answer in 150 words)
Introduction
Nuclear and mitochondrial DNA differ in almost every structural and transmission property, and it is these differences that decide what each can be used to reconstruct.
Body
1. Structure and organisation: nuclear DNA is about 3.2 billion base pairs on 46 linear, histone-bound chromosomes, with roughly 20,000 genes, introns and vast non-coding tracts. Mitochondrial DNA is a circular molecule of 16,569 base pairs carrying 37 genes, with no introns and a control region holding the hypervariable segments.
2. Inheritance and dynamics: nuclear DNA is biparental, Mendelian, present in two copies and reshuffled by recombination each generation. Mitochondrial DNA is maternally transmitted, effectively haploid and non-recombining, present in hundreds to thousands of copies per cell, subject to heteroplasmy and a germline bottleneck, and mutating about ten times faster.
3. What each is used for: mtDNA traces maternal lineages and haplogroups, and its copy number makes it recoverable from degraded and ancient bone. Nuclear and Y-chromosomal markers yield admixture proportions, paternal lineages and STR identification.
Conclusion
Neither substitutes for the other. Mitochondrial data give one deep lineage cheaply; nuclear data give the population's actual ancestry.