Micro Final

31. Which is not used when trying to ensure that autoclaving has achieved sterility? a) internal devices to maintain proper temperature b) tapes impregnated with the word "sterile" when proper temperature has been reached c) pasteurization by heating to 62.9 C for 30 minutes d) autoclaving heat-resistant endospores such as Bacillus stearothermophilus

C

33. Which of the following properties are exclusive to tRNA? A) combines with specific proteins to form ribosomes B) carries information from DNA for synthesis of a protein C) molecules contain an anticodon D) contains the nucleotide thymine

C

37. The first person to use a microscope to observe living cells was A) Robert Hooke B) Matthias Schleiden C) Anton van Leeuwenhoek D) Louis Pasteur

C

39. Prophages are responsible for production of the toxins found in A) staphylococcusaureus B) micrococcus luteus C) clostridium botulinum D) streptococcuslactis

C

39. Which of these statements about eukaryotic cell division is false? A) the nuclei of eukaryotic cells divide via the process of mitosis B) haploids are cells that receive only one chromosome from each pair of chromosomes C) a single round of mitosis results in the production of four haploid cells D) during mitosis the nuclear envelope breaks apart and the spindle apparatus forms

C

40. Mitochondria A) are responsible for converting sunlight to chemical energy B) are present only in photosynthetic organisms C) have a double membrane D) are responsible for protein synthesis

C

43. Which of the following statements about heat is true? A) thermal death point is the time required to kill all bacteria in a culture B) moist heat penetrates substances more slowly than dry heat C) dry heat leads to oxidation of molecules D) moist heat disrupts covalent bonds

C

45. A DNA mutation that results in no change in protein product produced is termed a A) missense mutation B) nonsense mutation C) silent mutation D) frameshift mutation

C

45. Enveloped animal viruses typically leave the host cell by A) hostcelllysis B) host cell rupture C) budding D) animal viruses never leave the host cell

C

47. The counterstain in a spore stain is A) malachite green B) crystal violet C) safranin D) methylene blue

C

5. Which of the following is not one of the phases of bacterial growth? A) lag phase B) stationary phase C) doubling phase D) log phase

C

9. The process of ________ results in the synthesis of a new protein. A) replication B) transcription C) translation D) transversion

C

17. Most human pathogens are A) psychrophiles B) mesophiles C) thermophiles D) acidophiles

b

11. Which is not used to measure the effectiveness of an antimicrobial agent? A) filter paper method B) phenol coefficient method C) use-dilution method D) plate count method

D

13. Bacilli produce fewer arrangements than cocci because A) cocci are smaller than bacilli B) bacilli only reproduce asexually C) bacilli divide along several different planes while cocci divide along a single plane D) cocci divide along several different planes while bacilli divide along a single plane

D

19. Lipids would be found primarily in the cell wall of A) Gram positive bacteria B) Gram negative bacteria C) Gram variable bacteria D) acid-fast bacteria

D

2. The type of cell reproduction in which a small, new cell develops from the surface of an existing cell and then separates from the parent cell is known as ________ and is the normal mode of replication in _____ . A) binary fission, bacteria B) binary fission, yeast C) budding, bacteria D) budding, yeast

D

20. An ion is all of the following except: A) a charged atom B) an atom that has lost or gained one or more electrons C) either a cation or an anion D) an atom with the same number of protons as electrons

D

20. To calculate the total magnification of a light microscope you must know A) the magnification of the objective and condenser lenses B) the magnification of the ocular and condenser lenses C) the magnification of objective, ocular and condenser lenses D) the magnification of the objective and ocular lenses

D

23. The end product of glycolysis is A) fructose-1,6-diphosphate B) 1,3 diphosphoglyceric acid C) phosphoenolpyruvic acid D) pyruvic acid

D

25. Formaldehyde, as an antimicrobial agent, is used for the following purposes A) food preservation B) disinfect skin and inanimate objects C) treat protozoan and fungal infections D) inactivate viruses without destroying antigenic properties

D

25. Select the true statement regarding yellow fever. a) Yellow fever is endemic to the United States. b) Yellow fever is only transmitted by one mosquito species c) Yellow fever is transmitted by ticks and mosquitoes d) Yellow fever is caused by a flavivirus.

D

26. In fermentation reactions occurring in yeast to produce wine, two products of the reaction are __________ and _________ A) acid; hydrogen gas B) hydrogen gas; propionic acid C) ethyl alcohol; methane D) carbon dioxide; ethyl alcohol

D

28. All of the following are considered microbes except A) viruses B) bacteria C) protozoa D) worms

D

29. Exoenzymes A) produced by gram positive rods act in the medium around the organism B) are released by the golgi apparatus into the cytoplasm where they act C) produced by gram negative rods act in the periplamic space D) two of the above

D

3. A small comma shaped bacteria is described as being a ________. A) spirochete B) bacillus C) spirillum D) vibrio

D

31. Each acetyl-CoA molecule will eventually produce ________ in the Krebs cycle. A) four pairs of electrons B) three molecules of NAD C) one molecule of GTP D) all of these

D

31. Three dimensional views of cells and other small objects could best be obtained using a A) phase contrast microscope B) dark-field microscope C) transmission electron microscope D) scanning electron microscope

D

33. Which of the following is not true of algae? A) they photosynthesize to produce their own food B) they are found in both fresh- and salt-water C) they have a nucleus D) they are a common cause of disease in humans

D

34. The prokaryotic aerobic metabolism of glucose produces a total (net) of ________ molecules of ATP. A) 24 B) 30 C) 34 D) 38

D

37. Fungi with no sexual stage in their life cycle are found in the phylum A) Zygomycota B) Ascomycota C) Basidiomycota D) Deuteromycota

D

37. Glucose A) is abundant in milk and fruit B) is a rare monosaccharide C) can be oxidized to form deoxy sugar or alcohol D) none of the above

D

38. Ultraviolet radiation A) is the same as Xrays B) is the same as gamma rays C) penetrates glass, cloth, paper and most other materials D) kills microorganisms by damaging DNA and proteins

D

39. With regard to the lactose operon, which of the following is false under conditions of low (or no) lactose? A) the RNA polymerase cannot transcribe structural genes B) the repressor is bound to the operator C) lactose is not bound to the repressor D) RNA polymerase can bind to the promoter

D

4. A parasitologist studies parasites. What does a mycologist study? A) protozoa B) how viruses cause disease and are involved in cancer C) the development of chemical substances to treat diseases D) fungi

D

43. In photosynthesis, light energy is used to A) break down proteins B) phosphorylate ADP to form ATP C) synthesize carbohydrates D) two of these choices

D

43. The field of ___________ involves studying how a person defends herself against microbial infection. A) molecular biology B) virology C) mycology D) immunology

D

43. Wuchereria bancrofti is the causative agent of A) trichinosis B) malaria C) sleeping sickness D) elephantitis

D

46. Arachnids have ____ legs and include _____ A) six, lice, fleas and flies B) six, ticks and mites C) eight, lice, fleas and mites D) eight, ticks and mites

D

5. Animals (humans for example) are A) photoautotrophs B) photheterotrophs C) chemoautotrophs D) chemoheterotrophs

D

5. While a doctor may diagnose and treat a patient who presents with a disease, an epidemiologist A) helps in the development and use of vaccines B) investigates what organism is responsible for a particular patient's disease C) figures out how to use microorganisms to clean up the environment D) studies the frequency and distribution of the disease in the community

D

50. Which of the following pH's would indicate the weakest acid A) 2 B) 3 C) 4 D) 5

D

2. Viruses are referred to as obligate parasites because A) viral DNA inserts itself into host DNA. B) they reproduce and then exit the cell. C) they use the host's energy to live. D) they use the host cell's nucleotides and enzymes to reproduce.

D - This answer is different on the quiz and is worded as follows: "D - They must use the host's machinery to synthesize components required for assembly into new virus particles."

23. Which statement is true for radioisotopes? A) radioisotopes have unstable nuclei that emit subatomic particles and radiation B) all radioisotopes have gained electrons C) radioisotopes are useful to guard against radioactive elements D) radioisotopes contain particles too large to form true solutions

A

27. When glucose is dissolved in water, the water is the ________ and the glucose is the ________. A) solvent, solute B) solvent, solution C) solute, solvent D) solute, solution

A

29. The concept of putting microbes to work to clean up the environment is called: A) bioremediation B) pasteurization C) immunization D) fermentation

A

3. A plasmid is a/an: A) extrachromosomal piece of DNA B) chromosomal site to which genetic activity can be traced C) body found in the cytoplasm that directs protein synthesis D) molecule that carries the genetic message of the chromosomal DNA

A

31. Much of the information about how viruses work has been gleaned from studying T even phages that infect A) bacteria B) human cells C) mammalian cells D) plant cells

A

33. Sporulation usually occurs in response to A) a decrease in the level of carbon or nitrogen B) an increase in temperature C) a decrease in the amount of water D) an increase in ultraviolet radiation

A

35. Because viruses such as bacteriophages lead to bursting of the bacterial host cell they are known as _______ viruses. A) lytic B) lysogenic C) recurring D) lethal

A

35. Lyophilization is A) freeze-drying B) refrigeration C) freezing D) heat-drying

A

38. A simple stain A) uses only a single dye B) requires only one step to stain a slide C) distinguishes between two different parts of an organism D) is composed of an equal balance of acid and basic dyes

A

41. A growth medium consisting of only known amounts of water, magnesium, calcium chloride, potassium and glucose would be considered A) a defined synthetic medium B) a complex medium C) a chemically nondefined medium D) two of the above

A

41. Phospholipids A) have a charged phosphate group that can mix with water and an insoluble fatty acid B) can serve as hormones C) always remain liquid at room temperature D) form straight chains in water

A

5. The formula for resolving power of a lens is λ/2NA (wavelength /2 x numerical aperture). What does this say about resolving power? A) the smaller the wavelength the greater the resolving power of the lens B) it is not related to the lens' numerical aperture C) we can not precisely calculate the resolving power of a lens D) a larger resolving power is indicative of a better lens

A

5. Which one of the following pairs is matched correctly? A) carbon-organic compounds B) glucose- hydrogen bonds C) ions-covalent bonds D) phosphate-enzyme

A

8. A virus's RNA can be directly used to synthesize proteins by the host cell after infection in a process shown below: A) RNA —> protein B) RNA RNA protein C) RNA DNA protein D) RNA RNA DNA protein

A

11. Atoms take part in bond formation to A) form polypeptides B) attain a stable electron configuration C) increase their charge density D) increase their energy

B

11. Diffraction occurs when A) light is reflected by an object B) light passes through a small opening C) light changes wavelengths D) light is absorbed by a normally transparent object (like a glass slide)

B

11. Koch's postulates were A) specific to anthrax and tuberculosis but don't apply to other diseases B) designed to establish a casual relationship between a causative microbe and a disease C) strict in that microorganisms isolated from experimentally inoculated hosts had to be different from the microorganism that was introduced into the host. D) interpreted as many organisms could cause the same disease

B

13. Sulfa drugs bind to the active site of the enzyme which normally converts PABA to folic acid, preventing the production of folic acid and, eventually, purine synthesis. In this case, the sulfa drug is acting as a/n A) allosteric inhibitor B) competitive inhibitor C) noncompetitive inhibitor D) uncompetitive inhibitor

B

18. Which of the following types of organisms would be most likely to have evolved to live in the large intestine, where there is a complete lack of free oxygen? A) obligate aerobe B) obligate anaerobe C) facultative anaerobe D) aerotolerant anaerobe

B

19. Which of the following viruses are known for causing latent infections? A) adenoviruses B) herpesviruses C) poxviruses D) parvoviruses

B

25. Organisms with special nutritional needs are said to be A) barophiles B) fastidious C) aerobes D) none of the above

B

26. The _____ portion of the cell membrane functions as a barrier while the ______ portion provides specific functions, including pumps, receptors, adhesion, etc. A) carbohydrate; nucleic acid B) lipid; protein C) lipid; carbohydrate D) nucleic acid; lipid

B

29. A typical fungus consists of a mass called a _____ made up of many threadlike structures called _____ A) thallus, mycelium B) mycelium, hyphae C) hyphae, mycelium D) mycelium, thallus

B

29. Which of the following statements about the genetic code is true? A) the first position of a codon determines the amino acid B) an amino acid can be specified for by more than one codon C) nonsense codons contain no information D) because DNA only contains three letters there are very few possible genes that can exist

B

32. Which of the following properties are exclusive to mRNA? A) combines with specific proteins to form ribosomes B) carries information from DNA for synthesis of a protein C) molecules contain an anticodon D) contains the nucleotide thymine

B

33. Endospores are usually induced to form when A) temperatures rise B) certain nutrients are depleted C) radiation is detected D) water is lost from the cell

B

39. During the metabolism of fats, the product of beta-oxidation enters A) glycolysis B) the Krebs cycle C) oxidative phosphorylation D) electron transport chain

B

40. In a Gram stain, the mordant is A) crystal violet B) iodine C) water D) alcohol

B

43. If the step involving iodine were left out of a Gram stain, which of the following would best describe the results? A) Gram negative cells would look Gram positive B) Gram positive cells would look Gram negative C) All rods would be pink, all cocci purple D) All cells would be purple

B

45. Bacteria that ferment lactose grow as red colonies on MacConkey agar while those that do not ferment lactose are pink. MacConkey agar can best be described as being A) selective B) differential C) complex D) enriched

B

45. During diffusion, molecules A) move from hotter areas to cooler areas B) move from areas of higher concentration to areas of lower concentration C) move from areas of lower concentration to areas of higher concentration D) expend energy to move around

B

45. When pairs of electrons are shared between two atoms, the result is a _______ bond. A) ionic B) covalent C) hydrogen D) carbonic

B

47. A metabolic pathway that is involved in both breakdown and synthetic reactions is properly termed A) catabolic B) amphibolic C) metabolic D) anabolic

B

47. Moist heat kills microorganisms by denaturing their A) lipids B) proteins C) carbohydrates D) nucleic acids

B

7. A host in which a parasite reproduces sexually is a A) primary host B) definitive host C) intermediate host D) reservoir host

B

8. Transcription results in the formation of what type of new molecule? A) DNA B) RNA C) Protein D) lipid

B

9. Extrachromosomal DNA in prokaryotic cells can be found in the form of A) chromosomes B) plasmids C) mitochondria D) chloroplasts

B

47. A mechanical vector A) lives on or in another organism at the expense of the host B) is simply along for the ride C) reproduces as an asexual form in the host D) infects by mechanical insertion of a syringe

B - This answer is worded differently on the quiz and reads as follows: "B - Simply carries microbes on the outside of its body"

13. Euglenoids contain a stigma, the purpose of which is to A) control the passage of molecules in and out of the cell B) communicate with other cells C) allow the protist to move toward light for photosynthesis D) digestnutrients

C

15. Acquired Immune Deficiency Syndrome (AIDS) is caused by a retrovirus. Which of the following best represents the genetic information flow used by retroviruses? A) DNA —> mRNA —> protein B) DNA —> protein C) RNA —> DNA —> mRNA —> protein D) RNA —> protein

C

17) Agents that adversely affect cell wall formation directly include: a) detergents b) alcohols c) crystal violet d) lactic acid

C

17. During DNA replication A) the leading strand is synthesized in the 3' to 5' direction B) the leading strand is synthesized discontinuously C) the lagging strand is synthesized in the 5' to 3' direction D) both strands are synthesized discontinuously

C

17. The atomic nucleus consists of: A) cations and anions B) protons, electrons and neutrons C) protons and neutrons D) solutes and colloids

C

17. Viruses were initially identified as small infectious agents that could pass through filters. How was it believed that these molecules could survive? A) they had small compact structures that allowed for the production of metabolites and replication B) they survived on the metabolites and poisons that pass through the filter C) they borrowed the use of existing metabolic and replicative mechanisms of the host cells they infected D) they are capable of capturing energy from the sun

C

17. Which one of the following pairs is mismatched? A) alcohol - fermentation B) pyruvate - glycolysis C) carbon dioxide - glycolysis D) NADH - Krebs cycle

C

19. Protozoa are A) multicellular B) mostly parasitic C) heterotrophic D) photosynthetic

C

23. A microscope that converts changes in the speed of light as it passes through an object into differences in brightness is a ________ microscope. A) bright field B) dark field C) phase-contrast D) Nomarski

C

24. Which bacterial genus normally lacks a cell wall? A) Mycobacterium B) Streptococcus C) Mycoplasma D) Bacillus

C

28. Mycology is defined as the study of A) microbes B) protists C) fungi D) plants

C

3. A leech that feeds on a person swimming in a pond then releases itself from the skin to return to the water is an example of a/an A) endoparasite B) permanent parasite C) temporary parasite D) reservoir host

C

3. An agent that inhibits the growth of bacteria is called a(an) A) antiseptic B) bactericide C) bacteriostatic agent D) Sanitizer

C

30. Dry heat does most of its damage against microorganisms by a) disrupting membrane lipids b) disrupting hydrogen bonds c) oxidizing molecules d) denaturing proteins

C

11. Viruses that have a single strand of RNA that acts as a template for DNA synthesis are known as A) retroviruses B) proviruses C) viroids D) bacteriophages E) lytic phages

A

13. Bacterial growth in colonies on agar plates A) have all phases of growth occurring simultaneously somewhere in the colony B) most growth occurs at the center of the colony C) involves budding of small new colonies from the surface of an existing colony D) have lag phase cells in the center of the colony, surrounded by a ring of cells in exponential phase

A

17. The lens closest to your eyes during a microscopic examination is the A) ocular B) objective C) condenser D) compound

A

23. Microbes have played important roles in genetics and in the discovery of DNA as the genetic material. What discoveries depended on bacteria? A) that the ability for a previously harmless bacteria to change into a disease causing bacteria was due to DNA B) the discovery of the intracellular reproduction of tobacco mosaic virus C) the development of the microscope D) the identification of a virus that causes yellow fever

A

23. Segments of DNA that do not code for proteins A) are called introns B) are found in all bacterial genes C) can be considered by your immune system as enemy DNA D) bind to proteins to form ribosomes

A