TCU DR JONES MICROBIOLOGY FINAL|
360+ ACTUAL QUESTIONS WITH 100%
VERIFIED ANSWERS | LATEST UPDATE
This constant doubling of the numbers only occurs as long as... - ANSWER -
nutrients for growth are available during the log phase of growth
A bacterial growth curve - ANSWER -illustrates the dynamics of growth
During the lag phase - ANSWER -no cell division occurs while bacteria adapt to
their new environment
The logarithmic (log) phase - ANSWER -exponential growth of the population
occurs during this phase
Human disease symptoms usually develop during it - ANSWER -Log Phase
Stationary phase - ANSWER -when reproductive and death rates equalize
Decline (exponential death) phase - ANSWER -the accumulation of waste
products and scarcity of resources causes it to enter
Endospores are a response to - ANSWER -nutrient limitation
Endospores are a highly resistant survival structure formed by species of _____
and _____ when nutrient supplies are low - ANSWER -Clostridium and Bacillus
Spores can lay dormant for years then germinate into a vegetative cell, withstand -
ANSWER -boiling water, alcohol and radiation
A stressed cell undergoes asymmetrical cell division creating... - ANSWER -
creating a small prespore and a larger mother cell
,The prespore contains - ANSWER -Cytoplasm, DNA, Dipicolinic
Dipicolinic acid - ANSWER -stabilizes proteins and DNA
The mother cell matures the prespore into an - ANSWER -endospore
The endospore then - ANSWER -disintegrates, freeing the spore
Endospores abilities - ANSWER -Are resistant to desiccation, heat, and undergo
very few chemical reactions
When environmental conditions are again favorable, the spore - ANSWER -
protective layers break down and the spore germinates into a vegetative cell
Why are Spores so hard to kill - ANSWER -They are not metabolically inert, have
a low water content, a thick spore coat, and contain lots of calcium and Dipicolinic
acid (10% by weight). All thought to contribute to their heat resistance
The basic requirements for a bacteria to grow include - ANSWER -Water,
Carbon/energy sources, Essential elements and organic growth factors,
Temperature, pH, Oxygen, Carbon dioxide, Osmotic conditions
obligate aerobes - ANSWER -which require oxygen to grow
Microaerophilic - ANSWER -prefer oxygen slightly lower than air
Anaerobes - ANSWER -do not or cannot use oxygen
Aerotolerant - ANSWER -are insensitive to oxygen but can grow in its presence
Obligate anaerobes - ANSWER -are inhibited or killed by oxygen
Facultative prokaryotes - ANSWER -grow either with oxygen, or in reduced
oxygen environments
, Capnophilic bacteria - ANSWER -require an atmosphere low in oxygen and rich
in carbon dioxide must incubate in a candle jar
Thioglycollate broth - ANSWER -can be used to test an organisms oxygen
sensitivity
Heat - ANSWER -is one of the most common physical control methods
At temperatures above the growth range - ANSWER -Proteins and nucleic acids
are destroyed, Water is removed, Thermal death time, Thermal Death Point
Thermal death time - ANSWER -each microbial species has a thermal death time
for a given temperature
Thermal death point - ANSWER -The minimum temperature at which it dies in a
given time period
Incineration - ANSWER -uses direct flame to kill microbes
Dry heat - ANSWER -requires long periods of exposure to high temperatures,
Moist heat - ANSWER -(like boiling water) is faster and effective at lower
temperature than dry heat
How does Dry heat destroy the bacteria - ANSWER -The heat changes microbial
proteins and removes water, slowly burning the microbes
How does Moist heat destroy the bacteria - ANSWER -It kills microbes by
denaturing their proteins
Pressurized steam is used in an _______ to sterilize a variety of objects -
ANSWER -Autoclave
360+ ACTUAL QUESTIONS WITH 100%
VERIFIED ANSWERS | LATEST UPDATE
This constant doubling of the numbers only occurs as long as... - ANSWER -
nutrients for growth are available during the log phase of growth
A bacterial growth curve - ANSWER -illustrates the dynamics of growth
During the lag phase - ANSWER -no cell division occurs while bacteria adapt to
their new environment
The logarithmic (log) phase - ANSWER -exponential growth of the population
occurs during this phase
Human disease symptoms usually develop during it - ANSWER -Log Phase
Stationary phase - ANSWER -when reproductive and death rates equalize
Decline (exponential death) phase - ANSWER -the accumulation of waste
products and scarcity of resources causes it to enter
Endospores are a response to - ANSWER -nutrient limitation
Endospores are a highly resistant survival structure formed by species of _____
and _____ when nutrient supplies are low - ANSWER -Clostridium and Bacillus
Spores can lay dormant for years then germinate into a vegetative cell, withstand -
ANSWER -boiling water, alcohol and radiation
A stressed cell undergoes asymmetrical cell division creating... - ANSWER -
creating a small prespore and a larger mother cell
,The prespore contains - ANSWER -Cytoplasm, DNA, Dipicolinic
Dipicolinic acid - ANSWER -stabilizes proteins and DNA
The mother cell matures the prespore into an - ANSWER -endospore
The endospore then - ANSWER -disintegrates, freeing the spore
Endospores abilities - ANSWER -Are resistant to desiccation, heat, and undergo
very few chemical reactions
When environmental conditions are again favorable, the spore - ANSWER -
protective layers break down and the spore germinates into a vegetative cell
Why are Spores so hard to kill - ANSWER -They are not metabolically inert, have
a low water content, a thick spore coat, and contain lots of calcium and Dipicolinic
acid (10% by weight). All thought to contribute to their heat resistance
The basic requirements for a bacteria to grow include - ANSWER -Water,
Carbon/energy sources, Essential elements and organic growth factors,
Temperature, pH, Oxygen, Carbon dioxide, Osmotic conditions
obligate aerobes - ANSWER -which require oxygen to grow
Microaerophilic - ANSWER -prefer oxygen slightly lower than air
Anaerobes - ANSWER -do not or cannot use oxygen
Aerotolerant - ANSWER -are insensitive to oxygen but can grow in its presence
Obligate anaerobes - ANSWER -are inhibited or killed by oxygen
Facultative prokaryotes - ANSWER -grow either with oxygen, or in reduced
oxygen environments
, Capnophilic bacteria - ANSWER -require an atmosphere low in oxygen and rich
in carbon dioxide must incubate in a candle jar
Thioglycollate broth - ANSWER -can be used to test an organisms oxygen
sensitivity
Heat - ANSWER -is one of the most common physical control methods
At temperatures above the growth range - ANSWER -Proteins and nucleic acids
are destroyed, Water is removed, Thermal death time, Thermal Death Point
Thermal death time - ANSWER -each microbial species has a thermal death time
for a given temperature
Thermal death point - ANSWER -The minimum temperature at which it dies in a
given time period
Incineration - ANSWER -uses direct flame to kill microbes
Dry heat - ANSWER -requires long periods of exposure to high temperatures,
Moist heat - ANSWER -(like boiling water) is faster and effective at lower
temperature than dry heat
How does Dry heat destroy the bacteria - ANSWER -The heat changes microbial
proteins and removes water, slowly burning the microbes
How does Moist heat destroy the bacteria - ANSWER -It kills microbes by
denaturing their proteins
Pressurized steam is used in an _______ to sterilize a variety of objects -
ANSWER -Autoclave
