In general, prokaryotic genome size is linked to its metabolism and interaction with the environment. Which type of prokaryote typically has the smallest genome?
A) parasite
B) endosymbiont
C) autotroph
D) free-living heterotroph

Question

Quizplus · Accepted Answer

Endosymbionts typically have the smallest genome size since they live within the host cell and rely on the host for many metabolic processes. They do not need many genes for environmental adaptation, so their genome size can be reduced. Parasites may have smaller genomes than free-living organisms, but this is not always the case. Autotrophs and free-living heterotrophs may require more genes for environmental adaptation, so they generally have larger genomes than endosymbionts.

In General, Prokaryotic Genome Size Is Linked to Its Metabolism