Microbiology

Chapter 3

1. Which of the five senses do microbiologists have to rely upon when studying microorganisms?

A) Sight

B) Smell

C) Hearing

D) Touch

E) Taste

2. Microbiologists must contend with unique problems when studying microorganisms. What is not one of these problems?

A) Pure cultures do not exist in nature

B) Groups of microbes must be separated from each other prior to study

C) Microbes must be grown under artificial conditions in the laboratory

D) Microbes are invisible and widely distributed

E) Contamination of a microbial culture is unlikely

3. Which of the "Five I's" promotes multiplication of microbes over a period of hours, days, or weeks?

A) Inoculation

B) Incubation

C) Isolation

D) Inspection

E) Identification

4. Which of the following is an example of a clinical sample?

A) Soil

B) Water

C) Feces

D) Sewage

E) Foods

5. What method of isolating bacterial colonies involves the use of a hockey stick?

A) Streak plate method

B) Loop dilution method

C) Pour plate method

D) Spread plate method

E) Colony method

6. Which method of obtaining isolated colonies is most commonly used for most applications?

A) Streak plate method

B) Loop dilution method

C) Pour plate method

D) Spread plate method

E) Colony method

7. Which of the following is incorrect regarding the use of animals in biology and medicine?

A) Animals are used in drug and vaccine research to prevent harmful effects on humans with untested materials

B) Animal models can be used to study disease progression

C) Animals are important sources of immune products

D) Animals are used to determine the toxicity of certain organisms

E) All bacteria require an animal host in order to be grown in the laboratory

8. For what purpose are semisolid media used?

A) Isolation of discrete colonies

B) Subculturing microorganisms

C) Obtaining growth throughout the tube

D) Determination of motility of a culture

E) Determination of viscosity of a culture

9. Solid media provide a solid surface on which discrete colonies may develop. The inclusion of what component in media allows for the formation of this solid surface?

A) Methylene blue

B) Agar

C) Thioglycollate

D) Indole

E) Hydrogen sulfide

10. What type of medium contains at least one component that is not pure and does not have an exact chemical formula?

A) Synthetic

B) Chemically defined

C) Complex

D) General purpose

E) Differential

11. Cultivation of fastidious microorganisms requires the use of what type of media?

A) Enriched

B) Enumeration

C) Selective

D) General purpose

E) Anaerobic growth

12. When unwanted microorganisms of unknown origin appear in a culture of known identity, the culture is said to be what?

A) Pure

B) Axenic

C) Contaminated

D) Mixed

E) Subcultured

13. Which of the following is defined as the ability to distinguish or separate two adjacent objects or points from one another in a microscopic specimen?

A) Image

B) Resolving power

C) Reflection

D) Illuminate

E) Refraction

14. How many magnifying lenses does a compound light microscope contain?

A) Zero

B) One

C) Two

D) Three

E) Four

15. Why must a drop of oil be placed between the tip of the oil immersion lens and the specimen on a glass slide?

A) The oil increases the degree of refraction

B) The oil helps to illuminate the specimen

C) The oil increases the total power of magnification

D) The oil decreases the numerical aperture

E) The oil prevents light from bending as it passes through the specimen

16. When a microscopic image is brightly illuminated, but is surrounded by a black field, what type of microscope is being used?

A) Phase-contrast

B) Fluorescence

C) Bright-field

D) Dark-field

E) Electron

17. What type of microscopy allows for the visualization of internal components within live, unstained specimens?

A) Phase-contrast

B) Fluorescence

C) Bright-field

D) Dark-field

E) Electron

18. What type of microscopy is commonly used in the clinical setting to diagnose infections caused by specific organisms?

A) Phase-contrast

B) Fluorescence

C) Bright-field

D) Dark-field

E) Electron

19. The type of microscopy in which the surface of a specimen is bombarded with electrons is known as what?

A) Bright-light

B) TEM

C) SEM

D) DIC

E) Phase-contrast

20. Bacteria stain more readily when what type of stain is utilized?

A) Dye

B) Anionic

C) Acidic

D) Negative

E) Basic

21. Negative staining is useful for observing the presence of what?

A) Capsule

B) Motility

C) Endospores

D) Mycolic acid

E) Flagella

22. Why would a differential stain be used to stain a microscopic specimen?

A) Because simple stains are ineffective

B) Because bacteria require the use of more than one dye to become visible

C) Because differential stains contain both a negative and a positive dye

D) Because differential stains contrast two cell types or cell structures

E) Because simple staining is a complex procedure, whereas differential staining is straightforward

23. Which of the following stains is not a differential stain?

A) Gram

B) Acid-fast

C) Endospore

D) Nucleic acid

E) Flagellar

24. When performing the Gram stain, what type of specimen is used?

A) Live

B) Heat-fixed

C) Unstained

D) Metal-coated

E) Those sectioned into thin slices

25. Both simple and differential stained specimens allow for the visualization of all but which of the following?

A) Cell shape

B) Presence or absence of certain structures

C) Arrangement of groups of cells

D) Biochemical composition of the specimen

E) Motility