exam 4 chap 28 biology

74. What general feature is necessary to consider an organism a microbe? A. small enough that a microscope is required to see them B. multicellular C. heterotrophic D. sexual reproduction E. use aerobic respiration for metabolism

A. small enough that a microscope is required to see them

78. What feature enables the archaea to survive in harsh environments? A. their plasma membranes and cell walls B. their metabolism C. the ability to form multicellular organisms D. their reproductive capabilities E. their nucleus

A. their plasma membranes and cell walls

10. Bacterial cells pick up free pieces of DNA from the medium pieces that were released from dead bacteria in a process called A. transformation. B. transduction. C. conjugation. D. infection. ' E. replication.

A. transformation.

30. If a virus is latent, A. it cannot be a retrovirus. B. the viral genome is reproduced along with the host cell. C. it must be a retrovirus. D. it is gaining a new envelope via "budding." E. it is easy to develop immunity against.

B. the viral genome is reproduced along with the host cell.

3. Which relationship is NOT correct? A. halobacteria—high salt concentration B. thermoacidophiles—cold Antarctic ice C. methanogens—swamps and marshes D. cyanobacteria—photosynthesis E. methanogens—biogas and greenhouse warming

B. thermoacidophiles—cold Antarctic ice

76. Which of the following is a benefit of microbes? A. break down organic molecules B. Various microbes help protect us from harmful microbes. C. aid in digestion D. synthesize vitamins K and B12 E. All of the answer choices are benefits of microbes.

E. All of the answer choices are benefits of microbes.

71. The central dogma of genetics states that DNA directs protein synthesis and that information flows from A. protein RNA DNA B. protein DNA RNA C. RNA protein DNA D. RNA DNA protein E. DNA RNA protein

E. DNA RNA protein

60. The fact that a nucleic acid is a very complicated molecule suggests that A. the RNA-first hypothesis is impossible. B. the protein-first hypothesis is therefore the only plausible hypothesis. C. sophisticated enzymes were not present or available to synthesize it. D. no natural system could ever generate them. E. RNA could not have arisen on its own by chance, but required enzymes to guide the synthesis of nucleotides and nucleic acids.

E. RNA could not have arisen on its own by chance, but required enzymes to guide the synthesis of nucleotides and nucleic acids.

8. Which statement is true about bacteria? A. They contain a nucleus. B. They lack ribosomes. C. They usually lack a cell wall. D. They divide sexually. E. They contain a single, circular DNA molecule as the genetic material.

E. They contain a single, circular DNA molecule as the genetic material.

31. The life cycle stage of an animal virus during which a mature capsid forms around copies of the viral RNA genome is A. budding. B. attachment. C. biosynthesis. D. uncoating. E. assembly.

E. assembly.

22. Which of these is the most accurate description of a virus? A. a noncellular living organism B. one of the smallest bacteria known C. a member of the kingdom Virusae D. a cell at the boundary between living and nonliving things E. chemical complexes of RNA or DNA protected by protein

E. chemical complexes of RNA or DNA protected by protein

51. Which of the following forms of energy is NOT one of those thought to have been involved in the production of large organic molecules in the primitive reducing atmosphere? A. radioactivity B. electrical energy C. heat D. radiation from the sun E. sound

E. sound

50. Considering the various theories, the energy used in forming organic molecules in the primitive atmosphere could have come from all EXCEPT A. lightning. B. ultraviolet radiation. C. heat from volcanoes. D. electric spark. E. sound.

E. sound.

59. If the hypothesis that protocells were based on an "RNA world" is correct, which would NOT be necessary to shift to a "DNA world"? A. an enzyme or reaction capable of converting ribose to deoxyribose in nucleotides B. enzymes for reverse transcription of RNA into DNA C. new enzymes to replicate the DNA D. new enzymes for transcribing DNA back to RNA E. the presence of oxygen

E. the presence of oxygen

21. Which of the following is considered to be acellular? A. bacteria B. fungi C. algae D. protozoans ' E. viruses

E. viruses

45. Although microbes are often equated with pathogens, not all are pathogenic and some help humans maintain their health. Which of the following are synthesized by bacteria that live in the human intestine? A. folic acid and vitamin B12 B. insulin and vitamin K C. lipids and folic acid D. vitamin K and lipids E. vitamins K and B12

E. vitamins K and B12

79. The plasma membrane of archaea is composed of a phospholipid bilayer.

FALSE

81. Bacterial metabolism is quite diverse and can range from heterotrophic individuals that are anaerobic to ones that use mitochondria to run cellular respiration. rev:

FALSE

25. The capsid of a virus is composed of A. RNA. ' B. protein. C. DNA. D. cellulose. E. lipid.

B. protein.

36. Naked strands of RNA not covered by a capsid are A. archaea. B. retroviruses. C. viroids. D. prions. E. viruses.

C. viroids.

82. Describe the steps in viral replication.

1. Attachment: the spikes of the virus bind to a specific receptor molecule on the host cell. 2. Entry: the viral envelope fuses with the host cell membrane and allows the viral genetic material to enter the host cell. 3. Replication: viral enzymes make copies of the genome. 4. Biosynthesis: some of the RNA molecules serve as mRNA for production of capsids and spike proteins. 5. Assembly: mature caspid forms around a copu of the viral genome. 6. Budding: new viruses are released from the cell surface.

2. The archaea include all of the following EXCEPT the A. methanogens. B. lichens. C. halophiles. D. thermoacidophiles. E. prokaryotes.

B. lichens.

42. Louis Pasteur conducted an experiment to answer the question of whether or not living things can arise spontaneously from nonliving materials. In this experiment he used two flasks of sterile broth. How could this demonstrate the invalidity of spontaneous generation? A. In the flask in which no outside materials could enter, no growth occurred while growth did occur in the flask that allowed outside air to enter, demonstrating that the living things came from outside the sterile broth. B. No growth occurred in either flask, demonstrating that sterile broth could not promote growth. C. Both flasks showed growth, demonstrating that spontaneous generation does occur. D. While both flasks showed growth, the flask that did not allow air to enter showed a higher growth, demonstrating that while spontaneous generation does not occur that it does not take air to permit growth. E. No growth occurred in either flask, demonstrating that sterilizing the broth removed its nutrients so growth could not occur regardless of whether or not life was present.

A. In the flask in which no outside materials could enter, no growth occurred while growth did occur in the flask that allowed outside air to enter, demonstrating that the living things came from outside the sterile broth.

33. Which statement is NOT true about a retrovirus? A. It contains a DNA genome before transcription. B. It contains the enzyme reverse transcriptase. C. It is able to carry out transcription of RNA to DNA. D. Viral DNA remains in the host genome. E. Can be hidden from the host immune system.

A. It contains a DNA genome before transcription.

66. Which statement is NOT true about a protocell? A. It would have contained DNA as its genetic material. B. It would have been present before the development of a true cell. C. It would have had a lipid and protein membrane surrounding it. D. It would have contained a biochemical pathway for energy metabolism. E. The hydrophilic heads of the membrane would have pointed outwards while the hydrophilic tails would have pointed inwards.

A. It would have contained DNA as its genetic material.

80. Which description best fits a chemoautotroph bacteria? A. They reduce carbon dioxide to an organic compound by using energetic electrons derived from chemicals. B. They reduce carbon dioxide to an inorganic compound by using energetic electrons derived from chemicals. C. They run photosynthesis that uses solar energy to produce their own food. D. They transfer electrons to sulfate, producing hydrogen sulfate. E. All of the answer choices are descriptions of a chemoautotroph bacteria.

A. They reduce carbon dioxide to an organic compound by using energetic electrons derived from chemicals.

72. Biological evolution (the evolution of living cells) differs from chemical evolution (the evolution of the molecules that make living cells) in that biological evolution would have been possible only after the development of A. a membrane. B. nucleic acids. C. enzymes. D. a metabolic pathway. E. RNA and enzymes.

A. a membrane.

26. Some, but not all, viruses contain ______, located on their outer surface. A. a membranous envelope composed of the host's plasma membrane B. both DNA and RNA from the host C. either DNA or RNA D. a protein capsid E. a protein spore coat

A. a membranous envelope composed of the host's plasma membrane

39. Which group does NOT have members that cause human disease? A. archaea B. bacteria C. fungi D. prions E. viruses

A. archaea

28. Which stage of viral reproduction takes place when the spikes of the virus bind to a specific receptor molecule on the surface of a host cell? A. attachment stage B. penetration stage C. biosynthesis stage D. maturation stage E. release stage

A. attachment stage

73. Which of the following organisms is considered a microbe? A. bacteria B. snail C. eagle D. oak tree E. roundworm

A. bacteria

20. Which of the following associations is correct? A. herpesvirus—chicken pox B. Epstein-Barr virus—herpes C. viroid—shingles D. prion—influenza E. HIV—chicken pox

A. herpesvirus—chicken pox

29. Most viruses are A. much smaller than bacteria. B. usually more than 1 micron long. C. larger than protists. D. immeasurable. E. single celled.

A. much smaller than bacteria.

77. Which feature is lacking in the cell wall of archaea that will distinguish them from the bacteria? A. peptidoglycan B. phospholipids C. proteins D. polysaccharides E. None of the answer choices are lacking in the cell walls of the archaea.

A. peptidoglycan

64. A complex protein-rich cell shelters and supports the DNA genetic code, and the code is the blueprint for the cell proteins; thus is set the "chicken-or-the-egg" dilemma of which came first. This is probably solved by the discovery that A. polypeptides and RNA could have evolved simultaneously. B. reverse transcriptase can convert RNA back into DNA. C. all DNA and protein can be distributed evenly inside and outside the nucleus. D. some proteins are simply assemblages of guanine, cytosine, thymine, and adenine. E. viruses can give rise to all of the cell molecules.

A. polypeptides and RNA could have evolved simultaneously.

61. The synthesis of DNA or RNA from the organic soup would have been guided by the actions of enzymes in the A. protein-first hypothesis. B. RNA-first hypothesis. C. clay-catalyst hypothesis. D. chloroplast. E. DNA-first hypothesis.

A. protein-first hypothesis.

63. According to Fox's laboratory experiments, the protocell could have been composed A. only of carbohydrates. B. mostly of polypeptides. C. of phospholipids. D. of chitinous threads. E. of protein and RNA.

B. mostly of polypeptides.

37. Some human diseases appear to be due to protein agents that may convert other normal proteins in the cell to also become these agents. This new disease protein agent is called a(n) A. archeon. B. prion. C. cyanobacterium. D. phage. E. retrovirus.

B. prion.

57. The hypothesis that suggests that RNA and polypeptides might have evolved simultaneously was proposed by A. Stanley Miller. B. Alexander Cairns-Smith. C. Charles Darwin. D. Gunter Wachtershauser E. Sidney Fox.

B. Alexander Cairns-Smith.

55. Which of the following is the correct order, from simple to complex, showing the origin of life? A. proteins CH4 and NH3 amino acids C, H, O, N B. C, H, O, N CH4 and NH3 amino acid proteins C. C, H, O, N amino acids proteins CH4 and NH3 D. amino acids proteins C, H, O, N CH4 and NH3 E. CH4 and NH3 proteins C, H, O, N amino acids

B. C, H, O, N CH4 and NH3 amino acid proteins

9. Which of these is a correct description of a form of horizontal gene transfer in bacteria? A. Crossing-over occurs between paired chromosomes in meiosis. B. Conjugation occurs when a cell passes DNA to another cell by means of a sex pilus. C. Transformation occurs when a bacteriophage carries a bit of DNA from a previous host cell to a new host cell. D. Transduction occurs when a live bacterium picks up DNA from dead bacteria that have shed it into the environment of the living cell. E. Binary fission occurs when two bacteria cells exchange genetic information.

B. Conjugation occurs when a cell passes DNA to another cell by means of a sex pilus.

43. In addition to his work with bacteria, Louis Pasteur was also the one to name viruses. His work with rabies produced what breakthrough? A. He was the first to discover that viruses could be based on RNA rather than DNA. B. He developed a vaccine that he used on a young rabies patient. C. He was the first to see a virus under a microscope. D. He was the first to determine the life cycle of a virus. E. He invented the microscope.

B. He developed a vaccine that he used on a young rabies patient.

40. Which statement is NOT true about prion diseases? A. Prions are believed to cause Creutzfeldt-Jakob disease (CJD). B. Prions lack a nucleus but must form DNA/RNA at some time in order to replicate. C. Prions are misshapen proteins that cause other proteins to change shape. D. Mad cow disease (BSE) is spread by consumption of cattle feed contaminated with prions. E. The buildup of these abnormal proteins cause a loss of neurons.

B. Prions lack a nucleus but must form DNA/RNA at some time in order to replicate.

49. Pathogenic bacteria are becoming increasingly deadly as A. humans refuse to wash their hands frequently enough. B. antibiotic resistance builds when more and more humans take unnecessary antibiotics. C. they pick up genes from humans, allowing them to fool human body cells into thinking that they are harmless. D. humans lose their natural immunity to many pathogens through lack of exposure. E. there are an increasing number of side effects from antibiotics.

B. antibiotic resistance builds when more and more humans take unnecessary antibiotics.

68. Which term does NOT apply to the first protocell? A. fermentation B. autotrophic C. membrane-bound D. single-celled E. self-replicating

B. autotrophic

7. Which type of organism will form endospores when faced with unfavorable environmental conditions? A. viruses B. bacteria C. algae D. protozoans ' E. fungi

B. bacteria

27. In order to infect a cell, a virus must A. inject its protein into the cell while the nucleic acid remains attached to the host cell surface. B. have a special protein spike on its surface capsid that can interact with a receptor protein on the surface of the host cell. C. actively burrow through the cell wall or cell membrane of the host cell to reach the cell's nucleus. D. produce a special extension of its cytoplasm when it comes into contact with the appropriate host cell. E. have enzymes to break down the cell wall or cell membrane of the host cell.

B. have a special protein spike on its surface capsid that can interact with a receptor protein on the surface of the host cell.

67. Which of these would have been most likely to develop only after the formation of a true cell? A. autotroph B. heterotroph C. protocell D. microsphere E. proteinoid

B. heterotroph

70. Which type of nutrition is believed to have come first? a. autotrophic B. heterotrophic C. aerobic D. photosynthetic E. catalytic

B. heterotrophic

17. What is the evolutionary relationship among archaea, bacteria, and eukarya? A. Since archaea are the most primitive, archaean ancestors gave rise to bacteria that in turn gave rise to eukaryotes. B. All three domains are equally distant from the most primitive common ancestor, a protocell. C. Archaea and eukarya share nucleic acid similarities, so eukarya split off from archaea. D. Bacterial ancestors gave rise to both archaea and to eukaryotes as two separate side branches. E. Archaea ancestors gave rise to both bacteria and to eukaryotes as two separate side branches.

C. Archaea and eukarya share nucleic acid similarities, so eukarya split off from archaea.

16. How are the archaea different from bacteria? A. Archaea show the earliest form of photosynthetic ability. B. Bacteria lack the peptidoglycan cell wall found in the archaea. C. Archaea have a monolayer of lipids with branched side chains. D. Archaea have evolved far more advanced forms of metabolism than bacteria. E. Archaea have very delicate plasma membranes compared to more durable bacteria.

C. Archaea have a monolayer of lipids with branched side chains.

56. __________ showed that amino acids can polymerize abiotically when exposed to dry heat. A. A. I. Oparin B. Stanley Miller C. Sidney Fox D. Graham Cairns-Smith E. Charles Darwin

C. Sidney Fox

48. Which genus of bacteria causes more diseases in humans than any other? A. E. coli B. Staphylococcus C. Streptococcus D. Mycobacterium E. Clostridium

C. Streptococcus

24. Which of the following is NOT true about viruses? A. The genome may be DNA or RNA. B. The nucleic acid may be single or double stranded. C. They contain nucleic acid, protein, and mitochondria. D. They exhibit host specificity. E. They are obligate intracellular parasites.

C. They contain nucleic acid, protein, and mitochondria.

4. Which statement is NOT true about bacteria? A. They lack mitochondria. B. They lack a nucleus but contain DNA. C. They reproduce sexually. D. They occur in three basic shapes. E. They have a single circular chromosome.

C. They reproduce sexually.

1. Which type of prokaryotes are able to live in the most extreme environments? A. cyanobacteria B. anaerobic bacteria C. archaea D. heterotrophic E. aerobic bacteria

C. archaea

47. Bacteria cause diseases in humans when they A. rearrange the genes of the host to code for specific virulence factors that determine the type and extent of the illness. B. carry the same genes as the host organism, causing them to be indistinguishable from the host cell. C. carry the genes that code for virulent factors, causing them to be more harmful to humans. D. carry genes that allow them to become symbiotes. E. carry the genes of organisms like birds (bird flu) or pigs (swine flu).

C. carry the genes that code for virulent factors, causing them to be more harmful to humans

11. One bacterial cell passes DNA to a second cell through a sex pilus in the process of A. transformation. B. transduction. C. conjugation. D. infection. E. replication.

C. conjugation.

23. The innermost core of a virus's structure is made up of A. a membranous envelope. B. both DNA and RNA. C. either DNA or RNA. D. a protein capsid. E. a protein spore coat.

C. either DNA or RNA.

15. Metabolically, the archaea are A. photosynthetic. B. not metabolically active. C. heterotrophic and some are autotrophic as well. D. parasitic. E. all autotrophs.

C. heterotrophic and some are autotrophic as well.

13. To be an effective antibiotic or chemotherapeutic agent, it is necessary A. not to kill the human host or cause allergic reactions. B. to be able to kill a bacterial cell only. C. not to kill the human host or cause allergic reactions AND to be able to kill a bacterial cell only. D. to change the genome of the bacterial disease agent. E. to stop any universal living cell process.

C. not to kill the human host or cause allergic reactions AND to be able to kill a bacterial cell only.

53. Miller's laboratory experiments showed that A. the first cell was probably made of nucleic acids. B. it is possible to form protocells. C. the primitive gases can react together to produce small organic molecules. D. atmospheric pressure is required for life to begin. E. the earth is approximately 4.5 billion years old.

C. the primitive gases can react together to produce small organic molecules.

34. When an enveloped animal virus enters a cell during the entry stage, A. the next thing it does is assemble a new virus. B. the envelope is removed after the virus is inside the cell's nucleus. C. the protein capsid is removed through uncoating to expose the viral genome. D. it immediately integrates its nucleic acid genome into the host chromosomes. E. its cycle always results in the death of the animal cell.

C. the protein capsid is removed through uncoating to expose the viral genome.

62. Which theory would suggest that both polypeptides and RNA arose at the same time? A. Aleksandr Oparin's coacervate theory B. Stanley Miller's chemical soup theory C. Sidney Fox's protein-first hypothesis D. Alexander Cairns-Smith's simultaneous evolution of polypeptides and RNA E. Darwin's original theory of evolution, as written in Origin of Species

D. Alexander Cairns-Smith's simultaneous evolution of polypeptides and RNA

14. A new classification by domains separates prokaryotes into A. Archaea and Cyanobacteria. B. Bacteria and Cyanobacteria. C. photosynthetic bacteria and chemosynthetic bacteria. D. Archaea and Bacteria. E. autotrophs and heterotrophs.

D. Archaea and Bacteria.

41. Antonie van Leeuwenhoek was a Dutch tradesman and scientist who is famous for all but one of the following. Which is the exception? A. He thought that animals were able to arise spontaneously from inorganic sources. B. He was skilled at grinding glass and made improvements in the microscope. C. He was the first to see living organisms in a drop of water. D. He invented the microscope. E. He called the organisms that he saw in a drop of water "wee animals."

D. He invented the microscope.

58. Which statement is NOT true about the RNA-first hypothesis? A. It is supported by the discovery that RNA can act as a catalyst. B. It is supported by the fact that RNA can act as a substrate and as an enzyme. C. It suggests that there was an "RNA world" about 4 billion years ago. D. It says that first RNA, then DNA, then proteins would have been necessary to interact in the chemical evolution that would have led to the development of the first cells. E. It suggests that only RNA was needed to progress to the formation of the first cells.

D. It says that first RNA, then DNA, then proteins would have been necessary to interact in the chemical evolution that would have led to the development of the first cells.

19. Which statement is NOT true about cyanobacteria? A. They were formerly called blue-green algae. B. Some release sulfur during photosynthesis. C. They can combine with fungi to form lichens. D. They are eukaryotic like fungi. E. They can colonize rocks.

D. They are eukaryotic like fungi.

46. Bacteria can be beneficial in all but which of the following ways? A. They can be used to clean up an oil spill in a process called bioremediation. B. They can be used in industry to generate products, particularly in food processing. C. They are present on the skin and help crowd out harmful bacteria. D. They are the primary producers of most ecosystems. E. They function in waste water purification to remove both organic and inorganic substances.

D. They are the primary producers of most ecosystems.

54. The organic soup in which the first cell is believed to have arisen probably contained A. isolated atoms. B. bubbling hot gases only. C. algae and other microscopic organisms. D. amino acids and other organic acids. E. nucleic acids and proteins.

D. amino acids and other organic acids.

5. The three shapes of bacteria are A. haplontic, diplontic, and alternations. B. anaerobic, aerobic, and facultative. C. heterotrophic, autotrophic, and chemosynthetic. D. bacillus, coccus, and spirillum. E. helical, spiral, and streptococci.

D. bacillus, coccus, and spirillum.

18. Which organisms form lichens? A. archaea and algae B. archaea and fungi C. cyanobacteria and algae D. cyanobacteria and fungi E. cyanobacteria and archaea

D. cyanobacteria and fungi

32. Which of the following is NOT a characteristic of a virus? A. acellular B. obligate parasite C. can be synthesized from chemicals in the laboratory D. diseases caused by viruses can be treated with antibiotics E. contain DNA or RNA

D. diseases caused by viruses can be treated with antibiotics

69. Some 20th-century authors wrote that the earliest protocells would have to be autotrophs. This concept appears to be A. correct, since heterotrophs would depend upon eating autotrophs. B. correct, since life is not possible without ATP which is only available in living systems. C. correct, since glycolysis and fermentation only occur after oxygen is present from photosynthesis. D. incorrect, since the primordial soup could contain many preformed food molecules. E. incorrect, since glycolysis and fermentation require complex enzymes for catalytic reactions.

D. incorrect, since the primordial soup could contain many preformed food molecules.

35. Influenza strains that sweep around the world often carry names such as Shanghai H1N1 or Mexico City H2N2. The viruses vary in H and N surface spikes because A. the viruses reproduce on their own and attack people in cities more often. B. these viruses emerged as stray DNA from the genomes of people in these cities. C. this is where the antibodies of immune people began to break down and the old virus was again virulent. D. infected people develop immunity to the original strain, and strains that mutate sufficiently to be outside the range of immunity are soon spread in highly populated areas. E. the H and N surface spikes are obtained from the human hosts.

D. infected people develop immunity to the original strain, and strains that mutate sufficiently to be outside the range of immunity are soon spread in highly populated areas.

52. Which of the following kinds of molecules is thought to have been absent from the primitive reducing atmosphere? A. water vapor (H2O) B. methane (CH4) C. hydrogen (H2) D. oxygen (O2) E. nitrogen (N2)

D. oxygen (O2)

65. In a liquid environment, ____ molecules will automatically form droplets called liposomes. A. amino acid B. protein C. glucose D. phospholipid E. nucleic acid

D. phospholipid

44. Microbiology is the study of microbes. These include all but which of the following? A. archae B. protists C. viroids D. plants E. fungi

D. plants

38. Bovine spongiform encephalopathy (BSE), or "mad cow disease," is caused by a(n) A. archeon. B. bacterium. C. cyanobacterium. D. prion. E. virus.

D. prion.

12. Which type of sexual exchange occurs among bacteria in which DNA is carried into a bacterial cell by means of a virus? A. binary fission B. conjugation C. transformation D. transduction E. budding

D. transduction

6. The response of bacteria that allows them to be identified as Gram-positive or Gram-negative is due to A. the type of DNA or RNA they contain. B. their ability or lack of ability to fix nitrogen. C. whether they are aerobic or anaerobic. D. whether their cell walls have a thin or thick layer of peptidoglycan. E. the rRNA sequences they demonstrate.

D. whether their cell walls have a thin or thick layer of peptidoglycan.

75. Compare the domains of Archaea and Eukarya in regards to their features.

Feature Archaea Eukarya Nucleus No Yes Organelles No Yes Introns Sometimes Yes Histones Yes Yes RNA polymerase Several types Several types Methionine is at start of protein synthesis Yes Yes

83. List the four stages that are thought to have led to the formation of the first cells.

Stage 1: Organic monomers evolved from inorganic compounds. Stage 2: Organic polymers formed by the joining of the organic monomers. Stage 3: Protobionts formed as the organic polymers became enclosed in a membrane. Stage 4: Living cells formed as protobionts acquired the ability to self-replicate.