Lab test 1

Question 1

Culture medium

Answer 1

Solution with nutrients needed for microbe survival (low molecular weight derived from enzymatic degredation of complex nutrients)

Question 2

Broth medium

Answer 2

Liquid medium that lacks a solidifying agent

Question 3

Agar

Answer 3

Broth medium supplemented with solidifying agent

Question 4

Agar liquid and solid temps

Answer 4

Liquid - 100

Solid 40

Question 5

Colony

Answer 5

Results from a single cell. Multiplies and represents the growth of a single species of microorganism

Question 6

Agar slants

Answer 6

Solid media in liquified state can be placed in test tube and allowed to harden at an angle

Question 7

Agar deep

Answer 7

Solid media in liquified state can be place in test tube and allowed to harden upright

Question 8

Agar plates

Answer 8

Poured into petri dishes

Question 9

Sterilization

Answer 9

Rendering a medium free from all forms of life

Question 10

Aseptic tecniques

Answer 10

Maintaining sterility

Question 11

What is used to cultivate microorganisms

Answer 11

Glass test tubes and petri dishes

Question 12

Subculturing

Answer 12

Microorganisms transferred from one vessel to another

Question 13

Pippete

Answer 13

Draws up liquids

Question 14

Normal/resident flora

Answer 14

Does not cause harmful effects

Question 15

Transient flora

Answer 15

Less permanent

Question 16

Why flame the loop before and after inoculating

Answer 16

To prevent contamination

Question 17

Why hold the test tube caps in your hand

Answer 17

To not contaminate the cap and bench

Question 18

Why cool the inoculating instrument before obtaining the inoculum

Answer 18

To not kill the organism

Question 19

Why flame the necks of test tubes before and after using

Answer 19

To kill any microbes on that part of the tube

Question 20

Purposes of subculturing procedures

Answer 20

To generate more cell colonies

Question 21

Why use straight needle to inoculate agar deep tube

Answer 21

To stab easily into the agar

Question 22

Lack of orange pigement on s. marcesans. Does this mean there is a contaminent

Answer 22

No. Not all variants produce the color and they produce it at different rates and it is affected by environmental conditions

Question 23

How can you tell if a culture is contaminated

Answer 23

1) Streak plate

2) Gram stain

Question 24

Can a pure culture be prepared from a mixed broth or mixed agar slant culture

Answer 24

No you have to do a streak plate

Question 25

There is more growth in Q4 than Q3. Explain why

Answer 25

Could have accidentally pulled from quadrant 1 into 4

Question 26

Why is a needle used to isolate individual colonies from a spread plate or streak plate

Answer 26

It is more precise and better able to pull cells

Question 27

How can you determine if the colony you chose to isolate is a pure culture

Answer 27

Gram stain

Question 28

Pure culture tecniques

Answer 28

Streak plate Pour plate loop dilution Spread plate

Question 29

What are agar deeps primarily used to study

Answer 29

Gaseous requirements of microorganisms

Question 30

Environmental factors that must be regulated

Answer 30

pH Osmotic pressure Temperature Gas requirements

Question 31

Why are petri dishes inverted

Answer 31

To prevent condensation from dropping onto the agar

Question 32

What is an incubator used for

Answer 32

Maintain optimal growth temperature

Question 33

Shaking waterbath

Answer 33

Provides rapid transfer of heat to vessel, increased aeration. Can only be used with broth medium

Question 34

What is a refridgerator used for

Answer 34

Storage of stock cultures and storage of sterile media to prevent dehydration

Question 35

How long should you allow the loop to cool for

Answer 35

20 to 30 seconds

Question 36

Slant to broth transfer

Answer 36

Obtain inoculum from slant and shake the loop or needle in broth

Question 37

Slant to agar deep transfer

Answer 37

Obtain inoculum from agar slant. Stab needle into agar deep (stab inoculation)

Question 38

Broth to slant transfer

Answer 38

Obtain a loopful of broth and run it over the slant in a zig zag pattern

Question 39

Streak plate

Answer 39

Rapid qualitative isolation method. Spreading a loopful of culture over an agar plate in quadrants

Question 40

Spread plate

Answer 40

Previusly diluted mixture of microorganisms is used

Question 41

Microbicidal effect

Answer 41

Kills right away

Question 42

Microbistatic effect

Answer 42

Inhibits reproductive capabilities of the cells

Question 43

Antiseptics

Answer 43

Chemical substances used on living tissue that kill or inhibit the growth of vegetative microbial life forms

Question 44

Disinfectants

Answer 44

Chemical substances that kill or inhibit growth of vegetative microbial forms on nonliving surfaces

Question 45

Chemotherapeutic agents

Answer 45

Chemical substances that destroy or inhibit growth of microorganisms in living tissues

Question 46

How to take care of spills

Answer 46

1. Flood area for 15-20 min with bleach 2. Place paper towel on the spill 3. Wipe clean after 15-20 min 4. Place contaminated towels in biohazard bag 5. Change gloves and wash hands

Question 47

Pure culture

Answer 47

A culture containing a single species

Question 48

Media

Answer 48

Liquid, solid, or semisolid solution of nutrients intended to support growth of microbes

Question 49

Nutrient agar

Answer 49

The typical solidifying agent of culture media made from seaweed extract containing mainly galactose. It lacks nutritional value. 1.5-1.8% agar concentration is needed for solid media

Question 50

Semisolid medium

Answer 50

Formed using an agar concentration of less than 1% . Used to test a species ability to grow at low oxygen levels and test for motility

Question 51

Culture

Answer 51

A visible mass of genetically identical cells grown on solid media

Question 52

Aseptic tecnique definition

Answer 52

Series of steps taken to prevent undesired contaminents from mixing with the desired culture as well as minimize the liklihood that those working with microbes as exposed to potential pathogens

Question 53

Incubator

Answer 53

Chamber used tomaintain optimal temperature for microbial growth

Question 54

Wire loop

Answer 54

Used to transfer small volumes of bacteria onto na surface of an agar plate or slant