Which of the Following LEAST Supports the Idea of Genome

Question

Which of the following LEAST supports the idea of genome reduction?
A) Pseudogenes found in some organisms are no longer expressed but have homology to functional genes in other species.
B) Virulence factors are found on pathogenicity islands.
C) Pathogenic shigellae lack major regions of genes that the closely related E. coli possesses.
D) Bacteria no longer need "pseudogenes" when growing in new environments.
E) Over half of the genome of the obligate intracellular pathogen, Mycobacterium leprae, is composed of pseudogenes that are no longer needed.

Accepted Answer

The presence of virulence factors on pathogenicity islands suggests that these genes are necessary for the pathogen's ability to cause disease, so they are not likely to be lost through genome reduction. The other choices all support the idea of genome reduction in some way.