Microbiology - Test Bank Study Guide Rated A+

Which organism displays the most recent evolutionary ancestry? a) Lobosea b) Basidiomycetes c) Acantharia d) Cryptomonads e) Apicomplexa {Ans: b) Basidiomycetes (short line at the end of the tree)}Within a population of E. coli cells, you frequently observe rod-shaped cells that are significantly larger than the rest. This species is not known to be pleomorphic. Which is the most likely explanation for your observation? a) Cells are different because nutritional needs are not being met b) Cells are at different stages of growth before binary fission c) Cells are contaminated with Staphylococcus d) Cells have lost their cell walls e) Cells have lost their plasma membranes {Ans: b) The most likely explanation for size discrepancies in E. coli cells are the *cells in different stages of growth before binary fission*}Which abilities might provide plausible mechanisms to explain the endosymbiont phenomenon? (Select all that apply) a) Development of a phagocytic capability by early eukaryal cells b) Development of a phagocytic capability by primitive aerobically respiring bacteria c) Development of membrane invasion by early eukaryal cells d) Development of membrane invasion by primitive aerobically respiring bacteria e) All are plausible strategies {Ans: a, d) Plausible mechanisms explaining the endosymbiont