WorksheetsCulturing Microorganisms
Total questions: 22
Worksheet time: 6hrs 30mins
What is the purpose of using a sterile loop when inoculating an agar plate?
To add nutrients to the agar
To prevent contamination
To increase microbial growth
To change the pH of the medium
At what temperature are most bacterial cultures incubated to promote growth?
20°C
25°C
37°C
45°C
Which of the following is a characteristic of a bacterial colony that can be observed on an agar plate?
Colour
Smell
Sound
Temperature
What is the typical incubation period for bacterial cultures on agar plates?
2-4 hours
12-24 hours
24-48 hours
72-96 hours
Which type of microbe is most likely to form a fuzzy colony on an agar plate?
Bacteria
Viruses
Fungi
Protozoa
What is the role of a selective medium in microbial testing?
To enhance the growth of all microbes
To inhibit the growth of certain microbes
To change the colour of colonies
To sterilise the agar plate
Which of the following is a common method for identifying bacterial colonies on an agar plate?
Smelling the plate
Observing colony morphology
Measuring the plate's temperature
Weighing the plate
What is the main reason for inverting agar plates during incubation?
To prevent contamination
To reduce moisture loss
To prevent condensation from dripping onto the agar
To increase microbial growth
Which of the following is a differential medium used to distinguish between different types of bacteria?
Nutrient Agar
MacConkey Agar
Sabouraud Dextrose Agar
Blood Agar
What is the purpose of using a control plate in microbial testing?
To provide nutrients for microbes
To serve as a comparison for experimental results
To increase the growth rate of microbes
To sterilise the environment
Which of the following conditions is NOT typically controlled during the incubation of agar plates?
Temperature
Humidity
Light exposure
Air pressure
What is the significance of colony size in microbial identification?
It indicates the age of the microbe
It helps determine the type of microbe
It shows the nutritional content of the agar
It reflects the pH level of the medium
Culture media provide microbes with:
CO2
O2
nutrients
agar
Bacteria growing in lab environments form:
colonies
gangs
spores
biofilms
The two most common types of media used in the laboratory are:
chemically defined & simple
agar & broth
simple & complex
differential & selective
A single colony:
is grown to provide a pure culture
starts as a single bacterial cell
consists of identical "clones"
all of these
A medium in which the exact chemical composition varies slightly between batches:
nonselective
differential
complex
simple
Fastidious organisms:
are motile
are anaerobic
require many growth factors
grow slowly
Acidophile:
microbes that grow best at pH>7
microbes that grow best at pH<7
microbes that grow best at pH=7
Microbes that grow and multiply in or on a culture medium are known as a:
bacteria
agar
culture
none of the above
Any material prepared for the growth of bacteria in a lab is called:
culture media
culture
media
microbe
Sulfur and phosphorus:
Are good for living things, but not required
Are enzymes needed for growth
Are critical elements needed for microbial growth
Are poisonous in low amounts
