Question 1

The prefix photo- indicates that an organism will make use of _______ for energy purposes.

Accepted Answer

A) chemicals 
B) organics 
C) light 
D) inorganics 
A) chemicals 
B) organics 
C) light 
D) inorganics C

Question 2

There are five stages of growth in an open system of culture.

Accepted Answer

A) True 
 B)False  False

Question 3

In the growth curve of a bacteria population,the bacteria are rapidly increasing in number in the

Accepted Answer

A) lag phase. 
B) exponential (log)phase. 
C) stationary phase. 
D) decline phase. 
E) boomer phase. 
A) lag phase. 
B) exponential (log)phase. 
C) stationary phase. 
D) decline phase. 
E) boomer phase. B

Question 4

High concentrations of salt and sugar in foods

Accepted Answer

A) are useful in preserving the food. 
B) tend to draw water out of a cell. 
C) tend to force water into a cell,causing plasmolysis. 
D) have no effect on water availability. 
E) are useful in preserving the food AND tend to draw water out of a cell. 
A) are useful in preserving the food. 
B) tend to draw water out of a cell. 
C) tend to force water into a cell,causing plasmolysis. 
D) have no effect on water availability. 
E) are useful in preserving the food AND tend to draw water out of a cell.

Question 5

A urine sample with more than 100,000 organisms is considered indicative of infection.A urine sample containing 5,000 bacteria,with a generation time of 30 minutes,sits for 3 hours before finally being assayed.How many bacteria will then be present within the sample?

Accepted Answer

A) 10,000 
B) 64,000 
C) 100,000 
D) 320,000 
A) 10,000 
B) 64,000 
C) 100,000 
D) 320,000

Question 6

A microbe is discovered growing near a deep sea thermal vent.When researchers bring a sample up to the surface and try to grow it in a lab at room temperature in a normal incubator,they are unsuccessful.Why?

Accepted Answer

A) The pressure isn't the same at sea level as it is on the ocean floor. 
B) Oxygen concentrations are very different between the two environments-it's possible the microbe is a strict anaerobe and is poisoned by the air (oxygen)in the lab. 
C) Salt concentrations might be different in the media the researchers are attempting to use and the salt water the microbe is used to living in.This might be causing osmotic pressure differences that the microbe can't tolerate. 
D) The temperature is probably different-the thermal vent would be very hot,while these researchers are trying to grow this microbe at room temperature.The enzymes in the cells are probably outside of their normal operating range at room temperature,and therefore nonfunctional. 
E) All of the above. 
A) The pressure isn't the same at sea level as it is on the ocean floor. 
B) Oxygen concentrations are very different between the two environments-it's possible the microbe is a strict anaerobe and is poisoned by the air (oxygen)in the lab. 
C) Salt concentrations might be different in the media the researchers are attempting to use and the salt water the microbe is used to living in.This might be causing osmotic pressure differences that the microbe can't tolerate. 
D) The temperature is probably different-the thermal vent would be very hot,while these researchers are trying to grow this microbe at room temperature.The enzymes in the cells are probably outside of their normal operating range at room temperature,and therefore nonfunctional. 
E) All of the above.

Question 7

Organisms that use CO2 as their source of carbon are called

Accepted Answer

A) organotrophs. 
B) heterotrophs. 
C) autotrophs. 
D) chemotrophs. 
A) organotrophs. 
B) heterotrophs. 
C) autotrophs. 
D) chemotrophs.

Question 8

During which phase of the bacterial growth curve does the total number of viable cells decline?

Accepted Answer

A) Stationary 
B) Lag 
C) Exponential 
D) Death 
A) Stationary 
B) Lag 
C) Exponential 
D) Death

Question 9

In nature,bacteria

Accepted Answer

A) often grow in close association with many other kinds of organisms. 
B) may remain in a prolonged exponential phase. 
C) frequently synthesize structures such as slime layers. 
D) may adhere to surfaces by means of pili and slime layers. 
E) All of the choices are correct. 
A) often grow in close association with many other kinds of organisms. 
B) may remain in a prolonged exponential phase. 
C) frequently synthesize structures such as slime layers. 
D) may adhere to surfaces by means of pili and slime layers. 
E) All of the choices are correct.

Question 10

A physician sends a stool sample to your lab,and wants to know if there are lactose fermenting microbes in the sample.How might you determine if these microbes are present or not from this mixed-microbe specimen?

Accepted Answer

A) Streak the sample for isolation on Thayer-Martin agar (which contains lactose and particular antibiotics for selectivity). 
B) Streak the sample for isolation on a blood agar plate (which contains lactose AND red blood cells that enrich the culture for iron). 
C) Streak the sample for isolation on a MacConkey agar plate (which contains lactose and a pH indicator that turns pink when acid byproducts are present). 
D) None of the above would work-there's no way to reliably determine this feature from the specimen given. 
A) Streak the sample for isolation on Thayer-Martin agar (which contains lactose and particular antibiotics for selectivity). 
B) Streak the sample for isolation on a blood agar plate (which contains lactose AND red blood cells that enrich the culture for iron). 
C) Streak the sample for isolation on a MacConkey agar plate (which contains lactose and a pH indicator that turns pink when acid byproducts are present). 
D) None of the above would work-there's no way to reliably determine this feature from the specimen given.

Question 11

In a rapidly multiplying bacterial population,cell numbers increase

Accepted Answer

A) arithmetically. 
B) logarithmically. 
C) linearly. 
D) indirectly. 
A) arithmetically. 
B) logarithmically. 
C) linearly. 
D) indirectly.

Question 12

A hot tub (approx.104$\circ$F or 40$\circ$C)would most likely contain

Accepted Answer

A) psychrophiles. 
B) partiers. 
C) thermophiles. 
D) mesophiles. 
A) psychrophiles. 
B) partiers. 
C) thermophiles. 
D) mesophiles.

Question 13

Late log phase of the bacterial growth curve

Accepted Answer

A) is marked by the production of primary metabolites. 
B) is marked by the production of secondary metabolites. 
C) is a transition into the death phase. 
D) shows a decline in cell numbers. 
A) is marked by the production of primary metabolites. 
B) is marked by the production of secondary metabolites. 
C) is a transition into the death phase. 
D) shows a decline in cell numbers.

Question 14

Mycobacterium leprae is typically found infecting the ears,toes,and fingers of its host due to its

Accepted Answer

A) requirement for well-oxygenated blood. 
B) easy access to those parts. 
C) need for cooler temperatures. 
D) long incubation period. 
A) requirement for well-oxygenated blood. 
B) easy access to those parts. 
C) need for cooler temperatures. 
D) long incubation period.

Question 15

One would expect most strict anaerobic organisms to have superoxide dismutase.

Accepted Answer

A) True 
 B)False

Question 16

You take absorbance readings on a spectrophotometer across a 6-hour culture of

Accepted Answer

A) Clearly,something is wrong with the spectrophotometer and it isn't measuring the correct values.Perhaps something is on the detector,making it register falsely high absorbance numbers. 
B) When we establish a growth curve,we should actually plot the log of the number of viable cells vs.time.However,a spectrophotometer can only measure absorbance.Absorbance is NOT the same as the number of viable cells.Many of the cells in the tube are most likely dead,but the machine can't discriminate between a live cell and a dead one.This keeps the absorbance high even into the death phase. 
C) It'll happen-E.coli just grow slowly.We haven't gotten to the end of the stationary phase yet.Be patient! 
D) Perhaps there's a big smudge of something on the tube that is blocking some of the light.This would lead to an elevated reading for every timepoint after the smudge was placed on the tube. 
E) coli cells growing in tryptic soy broth (TS
B) .Your absorbance readings clearly indicate a lag phase,a log phase,and a stationary phase.You come back in and take readings at 8,10,12,14,and 16 hours,but the absorbance number remains the same.Shouldn't it start coming down as the closed batch culture enters death phase? What's the most likely thing that is happening? 
A) Clearly,something is wrong with the spectrophotometer and it isn't measuring the correct values.Perhaps something is on the detector,making it register falsely high absorbance numbers. 
B) When we establish a growth curve,we should actually plot the log of the number of viable cells vs.time.However,a spectrophotometer can only measure absorbance.Absorbance is NOT the same as the number of viable cells.Many of the cells in the tube are most likely dead,but the machine can't discriminate between a live cell and a dead one.This keeps the absorbance high even into the death phase. 
C) It'll happen-E.coli just grow slowly.We haven't gotten to the end of the stationary phase yet.Be patient! 
D) Perhaps there's a big smudge of something on the tube that is blocking some of the light.This would lead to an elevated reading for every timepoint after the smudge was placed on the tube. 
E) coli cells growing in tryptic soy broth (TS
B) .Your absorbance readings clearly indicate a lag phase,a log phase,and a stationary phase.You come back in and take readings at 8,10,12,14,and 16 hours,but the absorbance number remains the same.Shouldn't it start coming down as the closed batch culture enters death phase? What's the most likely thing that is happening?

Question 17

When doing experiments with bacteria,

Accepted Answer

A) it is usually not necessary to standardize which stage of growth is used. 
B) it is best to use colonies as all the bacteria in a colony are at the same stage of growth. 
C) it is best to use bacteria from the same stage of growth. 
D) the age of the bacteria is not important. 
A) it is usually not necessary to standardize which stage of growth is used. 
B) it is best to use colonies as all the bacteria in a colony are at the same stage of growth. 
C) it is best to use bacteria from the same stage of growth. 
D) the age of the bacteria is not important.

Question 18

Small organic molecules that must be provided to bacteria in order for them to grow are called

Accepted Answer

A) minerals. 
B) growth factors. 
C) water. 
D) vitamins. 
A) minerals. 
B) growth factors. 
C) water. 
D) vitamins.

Question 19

In the cultivation of microaerophilic and anaerobic bacteria,

Accepted Answer

A) a(n)candle/anaerobe jar is sufficient. 
B) atmospheric oxygen in a(n)candle/anaerobe jar is converted to water. 
C) a packet containing chemicals that generate carbon dioxide and hydrogen is used in a(n)candle/anaerobic jar. 
D) oxidizing agents are incorporated into the media that react with oxygen. 
A) a(n)candle/anaerobe jar is sufficient. 
B) atmospheric oxygen in a(n)candle/anaerobe jar is converted to water. 
C) a packet containing chemicals that generate carbon dioxide and hydrogen is used in a(n)candle/anaerobic jar. 
D) oxidizing agents are incorporated into the media that react with oxygen.

Question 20

An organism called Bacillus fastidiosus

Accepted Answer

A) might be expected to be very flexible as to growth requirements. 
B) might be expected to be very strict as to its growth requirements. 
C) would probably be grown on amedium rich in growth factors. 
D) might be expected to have a rod shape. 
E) might be expected to be very strict as to its growth requirements,would probably be grown on amedium rich in growth factors ,AND might be expected to have a rod shape. 
A) might be expected to be very flexible as to growth requirements. 
B) might be expected to be very strict as to its growth requirements. 
C) would probably be grown on amedium rich in growth factors. 
D) might be expected to have a rod shape. 
E) might be expected to be very strict as to its growth requirements,would probably be grown on amedium rich in growth factors ,AND might be expected to have a rod shape.

Exam 4: Dynamics of Prokaryotic Growth

The prefix photo- indicates that an organism will make use of _______ for energy purposes.

There are five stages of growth in an open system of culture.

In the growth curve of a bacteria population,the bacteria are rapidly increasing in number in the

High concentrations of salt and sugar in foods

A urine sample with more than 100,000 organisms is considered indicative of infection.A urine sample containing 5,000 bacteria,with a generation time of 30 minutes,sits for 3 hours before finally being assayed.How many bacteria will then be present within the sample?

A microbe is discovered growing near a deep sea thermal vent.When researchers bring a sample up to the surface and try to grow it in a lab at room temperature in a normal incubator,they are unsuccessful.Why?

Organisms that use CO2 as their source of carbon are called

During which phase of the bacterial growth curve does the total number of viable cells decline?

In nature,bacteria

A physician sends a stool sample to your lab,and wants to know if there are lactose fermenting microbes in the sample.How might you determine if these microbes are present or not from this mixed-microbe specimen?

In a rapidly multiplying bacterial population,cell numbers increase

A hot tub (approx.104 ∘\circ∘ F or 40 ∘\circ∘ C)would most likely contain

Late log phase of the bacterial growth curve

Mycobacterium leprae is typically found infecting the ears,toes,and fingers of its host due to its

One would expect most strict anaerobic organisms to have superoxide dismutase.

You take absorbance readings on a spectrophotometer across a 6-hour culture of

When doing experiments with bacteria,

Small organic molecules that must be provided to bacteria in order for them to grow are called

In the cultivation of microaerophilic and anaerobic bacteria,

An organism called Bacillus fastidiosus

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Control of Microbial Growth

Metabolism: Fueling Cell Growth

The Blueprint of Life, From DNA to Protein

Bacterial Genetics

Biotechnology and Recombinant DNA

Identification and Classification of Prokaryotic Organisms

The Diversity of Prokaryotic Organisms

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunologic Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Genitourinary Tract Infections

Filters

Organisms that use CO₂ as their source of carbon are called

A hot tub (approx.104^$\circ$F or 40^$\circ$C)would most likely contain