Deck 17: The Microorganisms: Viruses, Bacteria, and Protists

Question 1

A bacteria's genetic material can include

A) a circular chromosome.
B) plasmids.
C) latent bacteriophage DNA.
D) a circular chromosome plus plasmids.
E) a circular chromosome, plasmids, and latent bacteriophage DNA.

Answer 1

E
Explanation: Every bacterium will have a chromosome, and many also have plasmids. If the bacterium has been infected with a bacteriophage that has a lysogenic reproductive cycle, the bacteriophage DNA may become integrated into the bacterial genome.

Question 2

Which of the following does not provide support for the endosymbiotic hypothesis?

A) Double membranes are around mitochondria and chloroplasts.
B) Mitochondria and chloroplasts have their own genomes.
C) Mitochondria and chloroplasts can synthesize proteins.
D) Mitochondria and chloroplasts contain genes that are strikingly similar to bacterial genes.
E) Mitochondria and chloroplasts contribute to different metabolic processes in the eukaryotic cell.

Answer 2

E
Explanation: If certain bacteria were engulfed by primitive eukaryotic cells and not digested, then they would acquire an extra membrane outside the original bacterial plasma membrane; this would explain the double membrane structure of mitochondria and chloroplasts. Since bacteria have their own genetic material, mitochondria and chloroplasts would be expected, as descendants of free-living bacteria, to have their own DNA and ribosomes. Thus, mitochondria and chloroplasts can carry out their own protein synthesis. The fact that mitochondria and chloroplasts contribute to different metabolic processes aerobic respiration and photosynthesis) in the cell does not provide direct support for the endosymbiotic hypothesis. However, it does make sense in light of the likely origins of these two organelles: the mitochondria are descendants of aerobic bacteria and the chloroplasts are descendants of cyanobacteria.

Question 3

Which of the following is not caused by an emerging virus?

A) acquired immunodeficiency syndrome AIDS)
B) chickenpox
C) bird flu
D) ebola
E) severe acute respiratory syndrome SARS)

Answer 3

B
Explanation: The herpes virus that causes chickenpox has, unfortunately, caused widespread illness for many years.

Question 4

Your task as a researcher is to develop a new drug to prevent retrovirus infections in newly exposed individuals. Which of the means listed is likely to be the most effective?

A) blocking enzyme action
B) destroying the viral genome
C) dissolving the capsid
D) preventing conjugation
E) disrupting the viral envelope

Question 5

A researcher infects a bacterium with a bacteriophage and notices that the infection does not immediately bring about the destruction of the host cell. Instead, the phage's genetic material is copied whenever the host reproduces. Which viral replication cycle is described here?

A) integration cycle
B) lysogenic cycle
C) biosynthetic cycle
D) lytic cycle
E) emergence cycle

Question 6

Animal viruses that have an envelope enter cells by

A) injecting their nucleic acid into the cell's cytoplasm.
B) fusing with the plasma membrane.
C) endocytosis.
D) plasmolysis.
E) either fusing with the plasma membrane or endocytosis.

Question 7

Why don't new biological macromolecules form abiotically from nonliving matter on the Earth today?

A) The special environmental conditions that are required do not exist.
B) There are not enough of the various elements needed.
C) There is not enough available energy.
D) There is no need for biological macromolecules.
E) Biological macromolecules do arise abiotically but are quickly consumed by organisms.

Question 8

Which of the following statements regarding bacterial endospores is false?

A) Endospores can survive in extremely harsh environments.
B) Within an endospore is a copy of the bacterial chromosome.
C) An endospore contains a small amount of cytoplasm material.
D) Endospores can survive for very long periods of time.
E) Endospores are reproductive structures.

Question 9

Which is the correct order of events in the lytic cycle of a bacteriophage?

A) attachment - penetration - biosynthesis - maturation - release
B) integration - penetration - biosynthesis - maturation - release
C) attachment - integration - biosynthesis - maturation - release
D) attachment - biosynthesis - maturation - release
E) penetration - attachment - biosynthesis - release - maturation

Question 10

Which means of genetic recombination in bacteria often make use of pili?

A) transformation
B) transduction
C) conjugation
D) both transformation and transduction
E) translocation

Question 11

Viroids and prions are alike in that both are infectious

A) cell types.
B) proteins.
C) molecules.
D) DNA.
E) RNA.

Question 12

Which of the following statements is not true of all viruses?

A) Viruses have an inner core of nucleic acid.
B) Viruses have a protein capsid.
C) Viruses are obligate intracellular parasites.
D) Viruses have envelopes.
E) Viral genomes may consist of either DNA or RNA.

Question 13

Citrus tristeza virus CTV) damages and kills susceptible citrus trees around the world. It can be spread by grafting of infected plants, and by aphids, insects with piercing mouthparts that they use to suck fluid from plants. Which of the following would not limit the spread of CTV?

A) use of insecticides to control the aphids
B) destruction of infected plants
C) production of transgenic citrus lines using genes from resistant plants
D) quarantine of fields with infected plants
E) application of antibiotic drugs to citrus plants

Question 14

What would you call a long chain of Streptococcus bacterial cells that are spherical in shape?

A) Streptococcus
B) Staphylococcus
C) Streptobacillus
D) Diplococcus
E) Streptospirillum

Question 15

Algae are commonly grouped by their type of

A) motility.
B) sexual reproduction.
C) pigment.
D) habitat.
E) feeding.

Question 16

Cell-like structures that may have resulted from macromolecular self-assembly are referred to as

A) prokaryotes.
B) protocells.
C) protoypes.
D) archaea.
E) protists.

Question 17

Retroviruses

A) contain DNA.
B) contain the enzyme reverse transcriptase.
C) produce RNA from DNA.
D) only invade plants.
E) produce protein directly from DNA.

Question 18

Cyanobacteria are important producers, more specifically called

A) photoautotrophs.
B) saprotrophs.
C) chemoautotrophs.
D) saproautotrophs.
E) photoheterotrophs.

Question 19

Which species are representatives of the green algae?

A) diatoms, Volvox, and Spirogyra
B) coralline algae, Volvox, and Spirogyra
C) Chlamydomonas, Volvox, and Spirogyra
D) Chlamydomonas, Volvox, and coralline
E) diatoms, Chlamydomonas, and Volvox

Question 20

A virus is specific to a particular type of host cell because

A) only certain hosts enter the environment inhabited by the virus.
B) not every virus contains metabolic machinery which can replace that of the host cell.
C) a glycoprotein on the viral capsid is a specific match to a receptor on the surface of a compatible host cell.
D) a host cell must be malfunctioning, or a virus cannot infect it.
E) the genome of the virus must be similar to that of its potential host.

Question 21

Some species of pathogenic bacteria are able to attack specific tissues in the human body due to structures called

A) adhesion factors.
B) bioremediaton factors.
C) flagella.
D) conjugation pili.
E) cilia.

Question 22

Which similarity is not shared between algae and plants?

A) Algae are eukaryotes.
B) Algae are photoautotrophs.
C) Algae are producers.
D) Algae were once classified as plants.
E) Most algae have some form of locomotion.

Question 23

Without bacteria in the environment,

A) adequate amounts of carbon would not be available to living organisms.
B) plants would not be able to grow due to lack of nitrogen.
C) bioremediation would have limited use as a tool to clean up pollutants.
D) there would be a shortage of decomposer organisms.
E) All of the choices are correct.

Question 24

In which type of environment would you be most likely to find methanogenic archaea?

A) hot, acidic
B) high salt concentration
C) anaerobic
D) aerobic
E) dry

Question 25

One group of protozoans which are nonmotile, produce spores, and have disease-causing species is the

A) foraminiferans.
B) trypanosomes.
C) sporozoans.
D) amoeboids.
E) radiolarians.

Question 26

A viroid is a naked, infectious _____ molecule.

A) protein
B) DNA
C) RNA
D) fatty acid
E) enzyme

Question 27

The _____ of a virus is enclosed by a _____ capsid.

A) nucleic acid; protein
B) membrane; protein
C) nucleic acid; membrane
D) protein; nucleic acid
E) RNA; DNA

Question 28

Naked strands of RNA not covered by a capsid are

A) viroids.
B) archaea.
C) prions.
D) retroviruses.
E) viruses.

Question 29

Which statement about slime molds and water molds is incorrect?

A) Both are eukaryotes.
B) Both have flagellated cells at some time in their life cycles.
C) Both form spores.
D) Both are chemoheterotrophs.
E) Both are fungi.

Question 30

Which type of archaea use a pigment related to the rhodopsin, a pigment found in human eyes, to absorb solar energy and pump chloride ions?

A) methanogens
B) halophiles
C) thermoacidophiles
D) alkaliphiles
E) psychrophiles

Question 31

Which of the following is not a similarity that protozoans have to animals?

A) Protozoans are chemoheterotrophs.
B) Most protozoans have some form of locomotion.
C) Protozoans are eukaryotes.
D) Protozoans were once classified as animals.
E) Protozoans are able to photosynthesize.

Question 32

You take a large sample of soil and put it all into individual pots. You then divide the pots into two groups. In the first group, every pot of soil has been sterilized, and thus contains no bacteria. In the second group, none of the pots of soil have been sterilized. You plant soybean seeds in all the pots. What would you expect to see as the seeds sprout and grow?

A) The plants growing in the sterile soil are bigger because they have not been exposed to any bacteria.
B) The plants growing in the non-sterile soil are bigger because they have mutualistic associations with nitrogen-fixing bacteria.
C) The plants growing in the sterile soil are bigger because they do not have to compete with nitrogen-fixing bacteria in order to obtain usable nitrogen.
D) The plants growing in the non-sterile soil are bigger because saprotrophic bacteria produce nutrients for them.
E) There is no difference in size between the plants growing in the sterile soil and those in the non-sterile soil.

Question 33

As a result of drinking contaminated water, a patient contracts amoebic dysentery. Would an antibiotic drug that inhibits peptidoglycan synthesis be beneficial in treating the amoeba infection?

A) Yes, because it would weaken the cell walls of the amoebas and cause them to die.
B) No, because amoeba are not bacteria and do not have peptidoglycan.
C) Yes, because antibiotics are always beneficial in treating infectious diseases.
D) No, because the cell walls of the amoeba that causes dysentery contain calcium carbonate, not peptidoglycan.
E) Yes, because the amoeba would not be able to reproduce.

Question 34

Bacteria that secrete digestive enzymes into their surroundings in order to decompose nonliving organic matter are called

A) chemoautotrophs.
B) symbiotes.
C) saprotrophs.
D) parasites.
E) photoautotrophs.

Question 35

Penicillin is an antibiotic drug that interferes with cell wall synthesis in bacteria, eventually resulting in cell death. What effect would you predict if you applied penicillin to archaea?

A) The archaea would die due to the weakening of their cell walls.
B) The archaea would not be affected, since they do not contain peptidoglycan.
C) The archaea would not be affected, since none of the archaea have cell walls.
D) The archaea would die due to their inability to synthesize protein for their cell walls.
E) None of the choices are correct.

Question 36

Which statement about bacteria is incorrect?

A) All bacteria are pathogenic to humans.
B) Bacteria are prokaryotes.
C) Most bacteria are chemoheterotrophs.
D) Bacterial cells reproduce by binary fission.
E) A bacterial cell has one chromosome.

Question 37

Which of these is mismatched?

A) cilia - bacteria
B) flagella - bacteria
C) flagella - slime molds
D) flagella - water molds
E) pseudopods - amoebas

Question 38

Archaea

A) have plasma membranes but lack cell walls.
B) have plasma membranes, and most have cell walls.
C) lack plasma membranes, but most have cell walls.
D) have neither plasma membranes nor cell walls.
E) have double plasma membranes and no cell walls.

Question 39

What evidence supports the idea that archaea are more closely related to eukaryotes than to bacteria?

A) Archaea and eukaryotes initiate transcription in the same fashion.
B) Archaea and eukaryotes both have cell walls with peptidoglycan.
C) Archaea and eukaryotes share some ribosomal proteins and have similar types of tRNA.
D) Archaea and eukaryotes initiate transcription in the same fashion, share some ribosomal proteins, and have similar types of tRNA.
E) None of the choices support a close relationship between eukaryotes and archaea.

Question 40

Which of these is mismatched?

A) malaria - protozoan
B) AIDS - virus
C) kuru - prion
D) tetanus - bacterium
E) food poisoning - archaea

Question 41

Which of the following are acellular?

A) prions
B) protozoans
C) archaea
D) algae
E) bacteria

Question 42

What is the main structural difference between a virus and a viroid?

A) Viroids do not have a capsid covering.
B) Viruses do not have a capsid covering.
C) Viroids contain DNA, while viruses do not.
D) Viruses contain RNA, while viroids do not.
E) There is no structural difference between the two.

Question 43

What feature enables the paramecium to move?

A) cilia
B) contractile vacuole
C) flagella
D) nucleus
E) pseudopodia

Question 44

African sleeping sickness is caused by a

A) trypanosome.
B) sporozoan.
C) prion.
D) bacterium.
E) virus.

Question 45

Which group of algae will have calcium carbonate within their cell walls?

A) red algae
B) green algae
C) brown algae
D) diatoms
E) filamentous algae

Question 46

Which group of organisms are viroids not viruses) most likely to parasitize?

A) plants
B) bacteria
C) fish
D) fungi
E) cattle

Question 47

Which of the following is not a characteristic of Paramecium?

A) a macronucleus produces mRNA and directs metabolic functions
B) motile with cilia
C) a micronucleus functions in reproduction
D) engulfs prey with pseudopods
E) chemoheterotrophic

Question 48

Which sporozoan characteristic is most consistent with a parasitic lifestyle?

A) lack of motility
B) chemoheterotrophism
C) unicellular
D) lack of light-absorbing pigment
E) eukaryotic

Question 49

Which of these is mismatched?

A) Paramecium - ciliate
B) Chlamydomonas - green alga
C) Plasmodium - sporozoan
D) Giardia - zooflagellate
E) Salmonella - amoeba

Question 50

Which of the following groups contains no photosynthetic organisms?

A) protists
B) bacteria
C) archaea
D) zooflagellates
E) prokaryotes

Question 51

Which of the following groups contains at least some members that have cell walls?

A) protists only
B) bacteria only
C) archaea only
D) prokaryotes only
E) protists, bacteria, and archaea

Question 52

Protists can be

A) unicellular only.
B) unicellular or colonial, but not multicellular.
C) colonial only.
D) colonial or multicellular, but not unicellular.
E) unicellular, colonial, or multicellular.

Question 53

What structure enables a plant virus to move from one plant cell to the next?

A) plasmodesmata
B) bacteriophages
C) capsids
D) insect vectors
E) recognition proteins

Question 54

Which of these occurs during the bacteriophage lysogenic cycle but not the lytic cycle?

A) attachment
B) penetration
C) integration
D) biosynthesis
E) maturation