Week 1 Labs

Question 1

Culture with one type of bacterial species in known as?

Answer 1

Pure

Question 2

A culture with more then one type of bacteria is known as?

Answer 2

Mixed

Question 3

Culture with unwanted organisms is called?

Answer 3

Contaminated

Question 4

What is the purpose of the aseptic techinque?

Answer 4

Avoid contamination

Question 5

How bacterial growth is bacterial growth detected on broth medium? Solid medium?

Answer 5

Turbidity (cloudness), colonies.

Question 6

What is the function of an autoclave in media preparation?

Answer 6

To sterilize the media of both vegetative cells and spores.

Question 7

How high should the bunsen burner flame be?

Answer 7

10cm high

Question 8

What part of the bunsen burner flame is hottest?

Answer 8

Blue cone is the coolest and the top of the cone is the hottest.

Question 9

Subcluturing

Answer 9

Providing the organism with a fresh medium

Question 10

inoculum vs inoculation

Answer 10

The organism is the inoculum while the process of transferring them to a new medium is inoculation.

Question 11

incubation period and temp for cultures?

Answer 11

30-37 C for 18-25 hours

Question 12

Sterilization

Answer 12

process that achieves a microbe-free medium

Question 13

Vegetative cells vs. Spores

Answer 13

Vegetative is actively growing and sores of environmental resistant.

Question 14

Autoclave specifications

Answer 14

15psi, 121 C, 15-20 minutes.

Question 15

Why do you flame the loop prior to placing it into a culture?

Answer 15

To prevent contamination of both the primary and new culture.

Question 16

How often must bacteria be sub-cultured from a broth to maintain culture viability?

Answer 16

48 hours

Question 17

Flocculence, turbidity, pellicle

Answer 17

Flocculence- clumps
Turbidity- cloudness
Pellicle- film growth on surface.

Question 18

Possible sources of contamination when performing broth-broth sub culturing.

Answer 18

Loop not being sterilized properly, contamination by placing the cap on bench.

Question 19

How are broth cultures used in microbiology?

Answer 19

Used for testing and research.

Question 20

How are slant cultures used in microbiology lab and what are its advantages over other types of cultures?

Answer 20

Maintain stock cultures. Take up less room and less likely to be contaminated.

Question 21

What is added to broth to produce a solid medium?

Answer 21

Agar

Question 22

At what temp does solid medium melt? What temp does it solidify?

Answer 22

Melts at 97-100 C and solidifies at 42 C

Question 23

What is the ideal pouring temp of a solid medium?

Answer 23

50 C

Question 24

inoculum size

Answer 24

the needed concentration of microorganisms for a standard test