Which of the Following is True Regarding Escherichia Coli

Question

Which of the following is true regarding Escherichia coli?
A) Most of our understanding about mitosis comes from studies on this model organism.
B) It is a rod-shaped bacterium that can only grow in the gut of humans and other vertebrates.
C) Two strains of E. coli can differ by up to 0.1% in their genomes.
D) E. coli strain K-12 encodes about 4300 proteins.
E) The E. coli (strain K-12) genome is about 430 million nucleotide pairs long.

Accepted Answer

E. coli is a prokaryotic model organism; although the discovery of many fundamental molecular mechanisms were aided by studies using E. coli, the eukaryotic process of mitosis is best studied in simple eukaryotic cells. E. coli can be easily cultured in the lab in nutrient media. Its genome of 4.6 million nucleotide pairs codes for about 4300 different proteins. But this number is reported for the K-12 strain. Other strains can be different in up to 50% of their genes, a significant diversity which has been explained by the process of horizontal gene transfer.