Exam 27: Bacteria and Archaea

Use the following information to answer the question(s)below. The most recently discovered phylum in the animal kingdom (1995)is the phylum Cycliophora.It includes three species of tiny organisms that live in large numbers on the outsides of the mouthparts and appendages of lobsters.The feeding stage permanently attaches to the lobster via an adhesive disk and collects scraps of food from its host's feeding by capturing the scraps in a current created by a ring of cilia.The body is sac-like and has a U-shaped intestine that brings the anus close to the mouth.Cycliophorans are coelomates,do not molt (though their host does),and their embryos undergo spiral cleavage. -Bacteria perform each of the following ecological roles.Which role typically does not involve symbiosis?

All of the following are potential causes that may have contributed to the introduction and spread of the infection in the two tanks,with the exception of

Which of the following is least associated with the others?

Which two processes are responsible for the shape of the curve at Time B? 1)transduction 2)entry of single-stranded Hfr DNA 3)rolling circle replication of single-stranded Hfr DNA 4)activation of DNA pumps in plasma membrane

If all prokaryotes on Earth suddenly vanished,which of the following would be the most likely and most direct result?

Jams,jellies,preserves,honey,and other foodstuffs with high sugar content hardly ever become contaminated by bacteria,even when the food containers are left open at room temperature.This is because bacteria that encounter such an environment

Although not present in all bacteria,this cell covering often enables cells that possess it to resist the defences of host organisms,especially their phagocytic cells.

Which species is probably an important contributor to the base of aquatic food chains as a primary producer?

Broad-spectrum antibiotics inhibit the growth of most intestinal bacteria.Consequently,assuming that nothing is done to counter the reduction of intestinal bacteria,a hospital patient who is receiving broad-spectrum antibiotics is most likely to become

If new genetic variation in the experimental populations arose solely by spontaneous mutations,then the most effective process for subsequently increasing the prevalence of the beneficial mutations in the population over the course of generations is

Photoautotrophs use

In a hypothetical situation,the genes for sex pilus construction and for tetracycline resistance are located together on the same plasmid within a particular bacterium.If this bacterium readily performs conjugation involving a copy of this plasmid,then the result should be

Plantlike photosynthesis that releases O₂ occurs in

Which of the following describe all existing bacteria?

The typical prokaryotic flagellum features

Which of the following factors does not contribute to genetic diversity in prokaryotes?

Which of these statements about prokaryotes is correct?

The following questions refer to the information and figure below. In this eight-year experiment,12 populations of E.coli,each begun from a single cell,were grown in low-glucose conditions for 20 000 generations.Each culture was introduced to fresh growth medium every 24 hours.Occasionally,samples were removed from the populations,and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor)E.coli population. -Which term best describes what has occurred among the experimental populations of cells over this eight-year period?

Which of the following obtain energy by oxidizing inorganic substances-energy that is used,in part,to fix CO₂?

The thermoacidophile Sulfolobus acidocaldarius lacks peptidoglycan,but still possesses a cell wall.What is likely to be true of this species? 1)It is a bacterium. 2)It is an archaean. 3)The optimal pH of its enzymes will lie above pH 7. 4)The optimal pH of its enzymes will lie below pH 7. 5)It could inhabit certain hydrothermal springs. 6)It could inhabit alkaline hot springs.