Chapter 3

Question 1

The visible accumulation of microorganisms in or on a nutrient medium. Also, the propagation of microorganisms with various media

Answer 1

culture

Question 2

A nutrient used to grow organisms outside of their natural habitats

Answer 2

medium

Question 3

The implantation of microorganisms into or upon culture media.

Answer 3

inoculation

Question 4

Completely free of all life forms, including spores and viruses

Answer 4

sterile

Question 5

To isolate a sample culture in a temperature-controlled environment to encourage growth.

Answer 5

incubate

Question 6

Growth-supporting substance in fluid form

Answer 6

liquid media

Question 7

Nutrient media with a firmness midway between that of a broth (a liquid medium) and an ordinary solid medium; motility media

Answer 7

semisolid media

Question 8

Material used to promote the growth of a broad array of microbes

Answer 8

general purpose media

Question 9

A nutrient medium supplemented with blood, serum, or some growth factor to promote the multiplication of fastidious microorganisms

Answer 9

enriched medium

Question 10

An organic compound such as a vitamin or amino acid that must be provided in the diet to facilitate growth. An essential nutrient.

Answer 10

growth factors

Question 11

Requiring special nutritional or environmental conditions for growth. Said of bacteria

Answer 11

fastidious

Question 12

Nutrient media designed to favor the growth of certain microbes and to inhibit undesirable competitors

Answer 12

selective medium

Question 13

A single substrate that discriminates between groups of microorganisms on the basis of differences in their appearance due to different chemical reactions

Answer 13

differential media

Question 14

Any biological agent that is capable of destroying red blood cells and causing the release of hemoglobin.

Answer 14

hemolysin

Question 15

A growth medium that absorbs oxygen and allows anaerobic bacteria to grow

Answer 15

reducing medium

Question 16

A growth medium that contains sugars that are converted to acids through fermentation. Usually contains a pH indicator to detect acid protection

Answer 16

carbohydrate fermentation media

Question 17

Microbiological medium that is used to transport specimens

Answer 17

transport media

Question 18

Microbiological medium used to test the effects of specific treatments to bacteria, such as antibiotic or disinfectant treatment

Answer 18

assay media

Question 19

Microbiological medium that does not encourage growth and allows for the counting of microbes in food, water, or environmental samples

Answer 19

enumeration media

Question 20

A macroscopic cluster of cells appearing on a solid medium, each arising from the multiplication of a single cell.

Answer 20

colony

Question 21

A tool used in the microbiology laboratory sometimes comprised of a platinum or nichrome wire loop attached to a heat-proof handle

Answer 21

inoculating loop

Question 22

A container growing a single species of microbe whose identity is known

Answer 22

pure culture

Question 23

A sterile state such as a pure culture.

Answer 23

axenic

Question 24

To make a second-generation culture from a well-established colony of organisms

Answer 24

subculture

Question 25

A container growing two or more different, known species of microbes

Answer 25

mixed culture

Question 26

A medium that once held a pure (single or mixed) culture but now contains unwanted microorganisms

Answer 26

contaminated culture

Question 27

An impurity; any undesirable material or organism

Answer 27

contaminant

Question 28

In optics, the bending of light as it passes from one medium to another with a different index of refraction

Answer 28

refraction

Question 29

An image formed at the focal plane of a convex lens. In the compound light microscope, it is the image created by the objective lens

Answer 29

real image

Question 30

In optics, an image formed by diverging light rays; in the compound light microscope, the second, magnified visual impression formed by the ocular from the real image formed by the objective

Answer 30

virtual image

Question 31

The capacity of a microscope lens system to accurately distinguish between two separate entities that lie close to each other. Also called resolution

Answer 31

resolving power

Question 32

The measurement of the degree of light that is bent, or refracted, as it passes between two substances such as air, water, or glass

Answer 32

refractive index

Question 33

A method for coloring microbial specimens that involves a chemical that sticks to the specimen to give it color

Answer 33

positive stain

Question 34

A staining technique that renders the background opaque or colored and leaves the object unstained so that it is outlined as a colorless area

Answer 34

negative stain

Question 35

Type of positive staining technique that uses a single dye to add color to cells so that they are easier to see. This technique tends to color all cells the same color

Answer 35

simple stains

Question 36

A technique that utilizes two dyes to distinguish between different microbial groups or cell parts by color reaction

Answer 36

differential stains

Question 37

A differential stain for bacteria useful in identification and taxonomy. Gram-positive organisms appear purple from crystal violet mordant retention, whereas gram-negative organisms appear red after loss of crystal violet and absorbance of the safranin counterstain

Answer 37

gram stain

Question 38

A solution containing carbol fuchsin, which, when bound to lipids in the envelopes of Mycobacterium species, cannot be removed with an acid wash

Answer 38

acid-fast stain

Question 39

In describing microbial developmental stages, a metabolically active feeding and dividing form, as opposed to a dormant, seemingly inert, nondividing form

Answer 39

vegetative

Question 40

Any staining method that highlights the outermost polysaccharide and/or protein structure on a bacterial, fungal, or protozoal cell

Answer 40

capsule staining

Question 41

A staining method that highlights the flagellum of a bacterium

Answer 41

flagellar staining