Mycoplasma are among the smallest and perhaps the simplest self-replicating prokaryotes known.M.genitalium contains a genome of 0.58 Mb.Approximately how many genes does this bacterium contain?
A)426,000
B)3000
C)1200
D)between 400 and 550
E)12

Question

Quizplus · Accepted Answer

The average gene size in prokaryotes is around 1000 base pairs. M.genitalium has a genome size of 0.58 Mb or 580,000 base pairs. So, the number of genes can be estimated by dividing the genome size by the average gene size. 
Number of genes = Genome size / Average gene size 
Number of genes = 580,000 / 1000 
Number of genes = 580

Therefore, M.genitalium has between 400 and 550 genes, which is closest to option D.

Mycoplasma Are Among the Smallest and Perhaps the Simplest Self-Replicating