WorksheetsBacteria Growth
Total questions: 25
Worksheet time: 25mins
At stationary phase:
Death rate = growth rate
True
False
Cells separate to form 2 daughter cells that are genetically identical.
True
False
To prepare 100 ml of 2.5% nutrient broth using the nutrient broth powder provided: 2.5g nutrient broth powder, top up to 100ml with water.
True
False
For viable cell count by spread plate method, we should choose the plate with 40 - 400 colonies
True
False
When we refer to 'growth' with bacteria, we are talking about the population and not the size of the bacteria.
False
True
If the pattern of growth continues, how many bacteria will be in sample B when six hours have elapsed?
32
64
1024
2056
What is the optimum pH range for most bacteria to grow?
2-4
5-7
7-9
10-12
The reason bacteria don’t take over everything is because they must have the right conditions such as:
food source
carbon dioxide
moisture
oxygen
iron
The chemical growth requirements essential for bacterial growth are ...?
Water,carbon,Nitrogen & sulphur
Water
Water,carbon,oxygen,phosphorus,Nitrogen,sulphur and other trace elements
Environmental waste
Generation time of Escherichia coli is ...
20 hours
20 days
20 minutes
20 seconds
Which is the following the main requirement(s) for the bacteria to grow ?
Nutrient requirement
Oxygen requirement
Oxygen and nutrient requirement
Physical and chemical requirement
Psychrophiles are those bacteria that able to grow under........
0-20 C
25 - 40 C
50 - 60 C
70 - 110 C
Which term best describes a bacteria that can't exist in the presence of oxygen?
Obligate aerobe
Facultative aerobe
Obligate anaerobe
Facultative anaerobe
Microaerophlile
What is the primary phase of bacterial growth where cells are adjusting to their environment?
Lag phase
Log phase
Stationary phase
Death phase
Which of the following conditions is NOT typically required for bacterial growth?
Nutrient availability
Correct temperature
Presence of light
Moisture
In a laboratory experiment, a bacterial culture starts with 100 cells and has a generation time of 30 minutes. How many cells will be present after 2 hours?
400
800
1600
3200
Which method is commonly used to measure bacterial growth by counting colonies?
Spectrophotometry
Spread plate method
Gram staining
PCR
What is the term for bacteria that thrive in high salt concentrations?
Thermophiles
Halophiles
Acidophiles
Alkaliphiles
Which of the following is a common method to sterilize equipment to prevent bacterial contamination?
Autoclaving
Refrigeration
Filtration
Desiccation
What is the effect of antibiotics on bacterial growth?
They promote growth
They inhibit growth
They have no effect
They change the color of bacteria
Which of the following is a real-world application of controlling bacterial growth?
Food preservation
Photosynthesis
Genetic engineering
Weather forecasting
What is the role of oxygen in the growth of aerobic bacteria?
It is toxic
It is not required
It is essential
It is optional
Which of the following is a characteristic of the stationary phase of bacterial growth?
Rapid cell division
Nutrient abundance
Cell death exceeds cell growth
Growth rate equals death rate
What is the typical temperature range for mesophilic bacteria growth?
0-10°C
15-45°C
50-70°C
80-100°C
Which of the following is a factor that can limit bacterial growth in nature?
Unlimited nutrients
Lack of competition
Predation by other organisms
Constant temperature
