Indicate whether each of the following descriptions better applies to the genome of mitochondria (M) or nuclei (N) in vertebrates. Your answer would be a four-letter string composed of letters M and N only, e.g. MNMN.
( ) It has a higher percentage of noncoding DNA.
( ) It has a stricter codon usage.
( ) Its genes are present at higher copy numbers per cell.
( ) Its evolutionary clock ticks much faster.

Question

Indicate whether each of the following descriptions better applies to the genome of mitochondria (M) or nuclei (N) in vertebrates. Your answer would be a four-letter string composed of letters M and N only, e.g. MNMN.
( )	It has a higher percentage of noncoding DNA.
( )	It has a stricter codon usage.
( )	Its genes are present at higher copy numbers per cell.
( )	Its evolutionary clock ticks much faster.

Quizplus · Accepted Answer

Mitochondria have a dense packing of genes in their genome, a relaxed codon usage, and occasional variant genetic codes. Mutation rate is much higher for mitochondrial DNA, making it useful for phylogenetic studies on relatively recent evolutionary changes.

Indicate Whether Each of the Following Descriptions Better Applies to the Genome