Microbial Life: Prokaryotes and Protists - Renz Science

16.2 External features contribute to the success ofprokaryotesFigure 16.2D Some prokaryotes have external structures thatextend beyond the cell wall.Flagella– Flagella help prokaryotes move in their environment.– Hairlike projections called fimbriae enable prokaryotesto stick to their substrate or each other.Fimbriae© 2012 Pearson Education, Inc.16.3 Populations of prokaryotes can adapt rapidlyto changes in the environment Prokaryote population growth– occurs by binary fission,– can rapidly produce a new generation within hours, and– can generate a great deal of genetic variation– by spontaneous mutations,– increasing the likelihood that some members of the populationwill survive changes in the environment.16.3 Populations of prokaryotes can adapt rapidlyto changes in the environment The genome of a prokaryote typically– has about one-thousandth as much DNA as aeukaryotic genome and– is one long, circular chromosome packed into a distinctregion of the cell. Many prokaryotes also have additional small,circular DNA molecules called plasmids, whichreplicate independently of the chromosome.© 2012 Pearson Education, Inc.© 2012 Pearson Education, Inc.Figure 16.3AChromosomePlasmids16.3 Populations of prokaryotes can adapt rapidlyto changes in the environment Some prokaryotes form specialized cells calledendospores that remain dormant through harshconditions. Endospores can survive extreme heat or cold.© 2012 Pearson Education, Inc.4