Microbiology

Chapter 7

1. Extremophiles are most commonly what type of microorganism?

A) Algae

B) Protozoa

C) Yeasts

D) Archaea

E) Molds

2 Substances required by living organisms in relatively large quantities and which play principle roles in cell structure and metabolism are known as what?

A) Nutrients

B) Macronutrients

C) Micronutrients

D) Trace elements

E) Reservoirs

3. Which of the following defines a heterotroph?

A) An organism that must obtain its carbon in an organic form

B) An organism that does not require essential nutrients for growth

C) An organism that uses CO3-2 as its carbon source

D) An organism that produces all the trace elements it requires for growth

E) An organism that uses CO2 as its carbon source

4. Molecules that satisfy heterotrophic nutritional requirements include all but which of the following?

A) Water

B) Nucleic acids

C) Lipids

D) Carbohydrates

E) Proteins

5. Nitrogen is required for the production of what category of molecules?

A) Fatty acids

B) Phospholipids

C) Nucleotides

D) Carbohydrates

E) Cellulose

6. The primary sources of nitrogen for heterotrophs include all except which of the following?

A) Proteins

B) DNA

C) Glucose

D) RNA

E) Amino acids

7.

What is not a role of hydrogen within cells?

A) It is a major element in all organic compounds

B) It serves as the source of free energy in reduction-oxidation reactions

C) It forms hydrogen bonds between molecules

D) It determines the shape and stability of proteins by forming disulfide bonds

E) It maintains pH within the cell

8. Which organism is an example of a photoautotroph?

A) Protozoa

B) Algae

C) Fungi

D) Pathogenic bacteria

E) Animals

9. What nutritional category of microorganisms plays an important part in recycling inorganic nutrients?

A) Photoautotrophs

B) Chemoheterotrophs

C) Saprobes

D) Photoheterotrophs

E) Chemoautotrophs

10. The principal energy-yielding reaction in animals, most protozoa and fungi, and aerobic bacteria is known as what?

A) Anaerobic respiration

B) Fermentation

C) Photosynthesis

D) Aerobic respiration

E) Methanogenesis

11. The earth would gradually fill up with organic material, and nutrients would not be recycled if it were not for what group of organisms?

A) Parasites

B) Methanogens

C) Saprobes

D) Photoautotrophs

E) Lithoautotrophs

12. The more successful of the parasitic microorganisms have what type of effect on their host?

A) They share energy sources with their host.

B) They have no fatal effects on the host and eventually evolve to a less harmful relationship with the host.

C) They eventually kill the host cell.

D) They have not effect whatsoever on the host cell.

E) They cause an infection when the host is compromised.

13. Osmosis requires that a membrane have what property?

A) Allow for the expenditure of energy

B) Have carrier proteins that participate in transport

C) Be freely soluble to all solute molecules

D) Exhibit Brownian movement

E) Be selectively permeable to molecules other than water

14. Which of the following is not a property of the carrier proteins that participate in facilitated diffusion?

A) They are present in the cell membrane

B) They require the expenditure of energy in order to function

C) They exhibit specificity

D) They can become saturated

E) They exhibit competition

15. The most stable environment for cells exists in what type of solution?

A) Isotonic

B) Hypotonic

C) Saprobic

D) Pressurized

E) Hypertonic

16. What is not a feature inherent in active transport systems?

A) They transport nutrients against the natural diffusion gradient

B) They are made up of specific membrane proteins

C) They transport nutrients in the same direction as the natural diffusion gradient but at a faster rate

D) They form energy during transport

E) They are an efficient system for transporting carbohydrates, amino acids, organic acids, phosphates, and metal ions

17. For most microbes, environmental factors fundamentally affect the function of what?

A) Metabolic enzymes

B) Nucleic acids

C) Lipids

D) Polysaccharides

E) Cell membranes

18. How is Taq polymerase from Thermus aquaticus able to function when used in the polymerase chain reaction?

A) It has heat stable nucleic acids

B) It functions under extremely acidic conditions

C) It has a cell membrane that resists heat

D) It copies DNA fragments

E) It is a heat stable enzyme

19. What form of oxygen is not toxic to microorganisms?

A) OH-

B) H2O2

C) O2-

D) 1O2

E) O2

20. Which of the following describes anaerobic organisms?

A) They use gaseous oxygen in their metabolism

B) They lack the enzymes that use oxygen in metabolism and they lack the enzymes that process toxic oxygen products

C) They possess superoxide dismutase but not catalase or peroxidase

D) They posses the enzymes needed to process toxic oxygen products

E) They metabolize by aerobic respiration when oxygen is present but undergo anaerobic respiration in the absence of oxygen

21. Microorganisms that are sometimes found growing in jellies, syrups, and brines are known as what?

A) Acidophiles

B) Halophiles

C) Neutrophiles

D) Osmophiles

E) Barophiles

22. What term is defined as an interrelationship between two or more free-living organisms that is beneficial to both but not necessary for the survival of either?

A) Synergism

B) Mutualism

C) Commensalism

D) Parasitism

E) Antagonism

23. Bacteria divide by a process known as what?

A) Budding

B) Snapping division

C) Binary fission

D) Zygote fusion

E) Endospore formation

24. Which of the following does not contribute to the initiation of the stationary phase of bacterial growth?

A) Depletion of nutrients and oxygen

B) Accumulation of organic acids

C) The generation time of the dividing organisms

D) A drop in the pH of the growth medium

E) Increased density of the organisms

25. What statement regarding bacteria in the exponential phase of growth is incorrect?

A) They do not influence the course of an infection

B) They are more susceptible to antimicrobial agents

C) They are more numerous and virulent than bacterial in the later growth phases

D) They are more likely to be passed from an infected patient to others

E) They will show their natural size and correct reaction when stained