1. Which prokaryotic cell is correctly matched with its morphology (shape)? 1.spirillum, is spherical 2.bacillus, is spherical 3.coccus, has one or more twists like a spiral 4.bacillus, is shaped like a small rod or staff 12345

2. The cell wall of bacteria is ________. 1.made of cellulose 2.made of peptidoglycan 3.inside the plasma membrane 4.present in all bacterial species 12345

3. Gram staining ________. 1.turns Gram-positive species pink 2.turns Gram-negative species purple 3.turns Gram-positive species purple 4.requires three steps: exposure of the bacteria to purple dye, then iodine, and finally an alcohol wash 12345

4. Photoheterotrophic prokaryotes ________. 1.get energy from the sun and use organic compounds as their carbon source 2.get nutrients from a living host 3.get carbon from carbon dioxide, and energy from oxidizing compounds such as iron or sulfur 4.are self-feeders who make their own food by photosynthesis 12345

5. Bacterial chromosomes are ________. 1.arranged in pairs, like those of humans 2.circular, single- stranded DNA 3.linear, double- stranded DNA 4.circular, double- stranded DNA 12345

6. During prokaryotic fission, the ________. 1.new DNA molecule produced is single-stranded 2.original DNA molecule and its copy slowly move apart by membrane growth between the two attachment sites 3.two DNA molecules are pulled apart by a spindle apparatus 4.two daughter cells produced are each unique 12345

7. A plasmid ________. 1.is a small, self-replicating circle of DNA with a few genes 2.is present in addition to the main chromosome in a bacterial cell 3.may encode instructions for making a sex pilus for conjugation 4.all of the choices 12345

8. Gene sequencing has ________. 1.revealed that cells in the domain Bacteria were the ancestors of eukaryotic cells 2.shown that organisms in the domain Archaea were the ancestors of eukaryotic cells 3.proved that neither Bacteria nor Archaea are related to eukaryotic cells 4.completely replaced numerical taxonomy as a method for classifying microorganisms 12345

9. A strain of bacteria ________. 1.is the same as a species 2.is a species that has not been officially classified yet 3.shows minor differences from its species, but not enough to be classified as a new species 4.is a pathogenic subgroup of a generally harmless species 12345

10. Agrobacterium tumefaciens ________. 1.causes a sexually transmitted disease 2.causes Lyme disease 3.is classified with the Proteobacteria, which are all Gram-positive 4.causes tumors in plants 12345

11. Magnetotaxic bacteria ________. 1.do not grow well in poorly oxygenated seawater 2.show collective behavior when food is scarce, massing to attack other bacteria 3.in the oceans respond to Earth's magnetic field by moving to greater depths 4.use their biological compass to remain in shallower, oxygenated water 12345

12. The six-kingdom classification system was replaced by a three-domain system because ________. 1.of evidence of the similarity of plant and animal cells on the molecular level 2.of evidence provided by molecular biologist Carl Woese on the rRNA of prokaryotes 3.proteobacteria were discovered to be more closely related to the Archaea 4.none of the choices 12345

13. Methanogenic archaeans ________. 12345 1.are frequently aerobic 2.have members that live near hydrothermal vents in 85°C water 3.make ATP by stripping electrons from hydrogen gas or acetate and transferring them to carbon dioxide, forming methane 4.may be found as symbionts in the guts of animals

14. Bacteriophages ________. 1.are a class of viruses which cause a variety of human diseases including gastroenteritis 2.infect plants and are responsible for substantially decreased agricultural productivity worldwide 3.have complex structures with base plates and tail fibers 4.are surrounded by lipid membranes derived from the host cell 12345

15. The Epstein-Barr virus causes ________. 1.the common cold 2.polio 3.infectious mononucleosis as well as several cancers 4.hearing loss, if left untreated 12345

16. Which statement about the multiplication cycle of herpes viruses is false? 1.herpes viruses bud from the plasma membrane of infected cells, wrapping themselves in a bit of the host cell's membrane 2.the infected host cell replicates many copies of the viral DNA 3.viral mRNA transcripts are translated into viral proteins by the host cell 4.herpes viruses use RNA as their genetic material, which they copy to DNA using their own reverse transcriptase enzyme 12345

17. A virus with a lysogenic pathway ________. 1.quickly destroys its host cell as new virus particles are released 2.allows infected cells to survive indefinitely 3.never reverts to a lytic pathway 4.contains genetic material coding for an enzyme which cleaves the host's chromosomal DNA, then integrates the viral genome into the host's sequence 12345

18. Which of the following statements about the Ebola virus is false? 1.Ebola is an emerging pathogen, which means that it has not been infecting humans for a very long time 2.Ebola outbreaks can be controlled by well-organized vaccination programs 3.Ebola kills between 70 and 90 percent of the people it infects 4.Ebola causes a dangerous hemorrhagic fever 12345

19. The bacteria Campylobacter, Salmonella, Staphylococcus aureus, and Listeria collectively are responsible for many cases of _________. 1.sexually transmitted disease 2.respiratory illness 3.foodborne disease 4.vCJD 12345

20. The prions responsible for causing vCJD are ________. 1.misfolded versions of a protein which trigger normal versions of that protein to become misfolded too. 2.spread by sneezing and coughing 3.viruses which hijack cell's reproductive machinery and force the cells to make more prions 4.the smallest known living organisms 12345