Microbiology 175 Study Guide for Microbial Growth and Genetics
What is the difference between individual and population growth?
Individual = single cell gets bigger
Population = reproduction (replication)
Describe the process of bacterial reproduction. How is this different from reproduction in
most plants and animals?
Bacteria reproduces asexually through binary fission and can be shown by an exponential growth
curve that reflects the bacteria’s doubling time
Most Eukaryotes reproduce sexually and have exchange in genetic material
How long does it take for bacteria to grow?
Depends on the bacterial species, it can range from hours to weeks
What factors can alter the growth of microbes?
Unfamiliar environment, metabolic waste build up, old bacterial cells start dying and
accumulating, lack of food and nutrients
Write out the bacterial growth equation, describing each of the terms.
Nf = (Ni)2^n
Nf = total bacteria
Ni = initial bacterial amount
n= number of generations that have passed
Draw the growth curve associated with the following situation. Make sure you label the
axes, and the different parts of the curve:
You inoculate a broth with a culture and the bacteria display typical bacterial growth
characteristics in static culture. The cells enter the death phase at 36 hours. At 37 hours
you add a whole bunch of sterile nutrients to the culture. Discuss how the bacterial
community in the tube will respond.
The phases are as follows for static cultures (lab grown bacteria with no interference):
What is the difference between individual and population growth?
Individual = single cell gets bigger
Population = reproduction (replication)
Describe the process of bacterial reproduction. How is this different from reproduction in
most plants and animals?
Bacteria reproduces asexually through binary fission and can be shown by an exponential growth
curve that reflects the bacteria’s doubling time
Most Eukaryotes reproduce sexually and have exchange in genetic material
How long does it take for bacteria to grow?
Depends on the bacterial species, it can range from hours to weeks
What factors can alter the growth of microbes?
Unfamiliar environment, metabolic waste build up, old bacterial cells start dying and
accumulating, lack of food and nutrients
Write out the bacterial growth equation, describing each of the terms.
Nf = (Ni)2^n
Nf = total bacteria
Ni = initial bacterial amount
n= number of generations that have passed
Draw the growth curve associated with the following situation. Make sure you label the
axes, and the different parts of the curve:
You inoculate a broth with a culture and the bacteria display typical bacterial growth
characteristics in static culture. The cells enter the death phase at 36 hours. At 37 hours
you add a whole bunch of sterile nutrients to the culture. Discuss how the bacterial
community in the tube will respond.
The phases are as follows for static cultures (lab grown bacteria with no interference):
