What are the differences between mitochondrial DNA and nuclear DNA?

Basis of differentiation 

Mitochondrial DNA (mtDNA)

Nuclear DNA (nDNA

Definition 

Refers to DNA located in the mitochondria of the cell

Refers to DNA located in the nucleus of the cell

Proportion of the cell’s total genetic composition 

Makes up 0.25% of the cell’s total genetic composition in animal cells

Makes up 99.75% of the cell’s total genetic composition  in animal cells

Location and enclosure 

Found freely floating in the mitochondrial matrix and is not enclosed by the nuclear membrane

Found in the nuclear matrix, enclosed by the nucleus and fixed to the nuclear membrane

Number of chromosomes

Consists of one chromosome 

Consists of multiple chromosomes

Genome structure and composition

Circular, closed structure made up of 16,569 DNA base pairs

Linear, open ended structure made up of 3.3 billion DNA base pairs

Inheritance and recombination

Is haploid – Chromosome is inherited from the mother to the offspring without undergoing genetic recombination

Is diploid – Chromosomes are inherited equally from both parents and undergo genetic recombination while transferring to the offspring

Gene encoding 

Contains 37 genes that encode 13 proteins, 22 tRNAs, and 2 rRNAs

Contains 20,000-25,000 genes coding for all the proteins necessary for its function, which also includes mitochondrial genes

Translation process 

Not all codons follow the universal codon pattern when they are translated into proteins

All codons follow the universal codon pattern when they are translated into proteins

Transcription process 

Gene transcription is polycistronic – the mRNA formed has  sequences that code for multiple proteins

Gene transcription is monocistronic – the mRNA formed has sequences coding for only a single protein

Mutation rate 

Has a higher mutation rate 

Has a lower mutation rate that’s less than 0.3%