What are the differences between mitochondrial DNA and nuclear DNA?

Question

Accepted Answer

There are several 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%

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%

Basis of differentiation

Mitochondrial DNA (mtDNA)

Nuclear DNA (nDNA

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