Lab Exam 1

Question 0

Colony

Answer 0

A visible population of microorganisms growing on a solid medium

Question 1

Agar

Answer 1

A carbohydrate derived from seaweed used to solidify a liquid medium.

Question 2

Inoculate

Answer 2

To transfer organisms to a medium to initiate growth

Question 3

Media

Answer 3

The substance used to support the growth if microorganisms

Question 4

Normal biota

Answer 4

(Normal flora)

The organisms usually found associated with parts of the body.

Question 5

Pathogen

Answer 5

An organism capable of causing disease.

Question 6

Ubiquity

Answer 6

The existence of something everywhere at the same time

Question 7

Aseptic

Answer 7

Free of contamination

Question 8

Incubate

Answer 8

Store cultures under conditions suitable for growth, often in an incubator.

Question 9

Pure culture

Answer 9

A population of cells resulting from the growth of a single cell.

Question 10

Sterile

Answer 10

Free of viable bacteria or viruses

Question 11

Streak plate

Answer 11

A technique for isolating pure cultures by spreading organisms on an agar plate.

Question 12

Compound microscope

Answer 12

A microscope with more than one lens system

Question 13

Condenser

Answer 13

A structure located below the stage that contains a lens for focusing light on the specimens as well as an iris diaphragm.

Question 14

Iris diaphragm

Answer 14

An adjustable opening that regulated the amount of light illuminating the specimen.

Question 15

Magnification

Answer 15

The microscopes ability to optically increase the size of a specimen

Question 16

Resolution

Answer 16

The smallest separation that two structural forms must have in order to be distinguished optically as separate.

Ex. 2 adjacent cilia

Question 17

Wet mount

Answer 17

A laboratory technique in which a microscopic specimen in liquid is placed on the surface of a slide and covered with a coverslip.

Question 18

Immersion Oil

Answer 18

Oil placed on a slide to minimize refraction of the light entering the lens.

Question 19

Refraction

Answer 19

The bending or light as is passes from one medium to another.

Question 20

Refractive index

Answer 20

The ratio of the velocity of light in the first two media to its velocity in the second medium as it passes from one medium into another medium.

Question 21

Capsule

Answer 21

A gelatinous material coating the outside of a cell.

Question 22

Differential stain

Answer 22

• A procedure that stains a specific morphological structure
• Typically a multiple stain

Ex. Gram stain & acid fast stain

Question 23

Inclusion bodies

Answer 23

Granules of storage material such as sulfur that accumulate within some bacterial cells.

Question 24

Micrometer (um)

Answer 24

The metric unit to measure bacteria.

1 meter = 1,000,000 micrometers
1 mm = 1,000 micrometers

Question 25

Negative stain

Answer 25

A simple stain in which the organisms appear clear against a dark background

Question 26

Parfocal

Answer 26

All the objective lenses of the microscope are in the same plane, so you don’t have to refocus when changing lenses.

Question 27

Simple stain

Answer 27

A procedure for staining bacteria consisting of a single stain

Question 28

Smear

Answer 28

A dried mixture of bacteria and water (or broth) placed on a glass slide for preparation for staining

Question 29

Counter stain

Answer 29

• A stain used to dye unstained cells

- contrasting color is differential stain

Question 30

Mordant

Answer 30

A substance that increases the adherence of a dye

Question 31

Peptidoglycan

Answer 31

The macromolecule making up the cell wall of most bacteria

Question 32

Vegetative cell

Answer 32

A cell that has not formed spores or other resting stages

Question 33

Peritrichous

Answer 33

The surface of the organism is covered with flagella, such as E. Coli

Question 34

Polar

Answer 34

A single flagellum at one or both ends of the organism

Ex. Pseudomonas

Question 35

Polar tuft (lophotrichous)

Answer 35

A tuft of flagella at one or each ends of the organism

Ex. Spirillum

Question 36

Chemically defined medium

Answer 36

A synthetic medium composed of inorganic salts and usually a carbon source such as glucose

Question 37

Complex medium

Answer 37

(Undefined medium)

• The exact amounts of chemical components and their composition are unknown.
• not measured

Question 38

Differential medium

Answer 38

Permits certain organisms to be distinguished from others by the appearance of their colonies.

Question 39

Enteric

Answer 39

Associated with the intestine

Question 40

Fastidious

Answer 40

Require growth factor

Ex. Staphylococcus

Question 41

Glucose mineral medium

Answer 41

A chemically defined medium containing glucose as a carbon source and salts (NH4Cl , KH2PO4) for a nitrogen and phosphate source

Question 42

Growth factor

Answer 42

A compound such as a vitamin or amino acid that is required by an organism to grow

Question 43

Rich (enriched) medium

Answer 43

• A medium, usually complex, containing many growth factors.
• sometimes blood or additional vitamins are added to permit the growth or organisms with special requirements.

Question 44

Selective medium

Answer 44

Medium formulated to permit the growth of certain bacteria, but not others.