Human and bacteria organise their DNA (making up their [blank_start]genes[blank_end]) into [blank_start]chromosomes[blank_end]. Humans have 46 of them, whereas bacteria often only have [blank_start]one[blank_end]. Unlike in human cells, bacterial chromosomes are often [blank_start]circular[blank_end].
Bacteria can also have 'extra-chromosomal' pieces of DNA. Label both types of genetic material on the diagram below.
Eukaryotic genomes are far smaller than bacterial genomes.
The smallest bacteria genome is Mycobacterium genitalium, consisting of 580,070 base pairs.
The study of bacterial [blank_start]genomes[blank_end] has been made far easier by the development of DNA [blank_start]sequencing[blank_end]. DNA sequencing allows us to determine the [blank_start]base[blank_end] [blank_start]pairs[blank_end] making up a genome.
Sequencing of entire bacterial genomes is extremely useful for two reasons: it allows us to predict the function of previously unidentified [blank_start]genes[blank_end] and it allows us to map the relationships of different bacteria to form a tree of [blank_start]life[blank_end].