Chapter 6-Test Questions

A microbe recovered from an environmental sample grows on a medium composed of agar and a mix of salts.  This Agar is NOT digested during incubation.  The growth rate increased in HIGH C)2 conditions.  This organism is likely a (n)?
a) hetertroph
b) autotroph
c) chemotroph
d) halophile

An aquatic microbe that can grow only near the surface of the H2O is probably which of the following?
a) Phototroph
b) Heterotroph
c) Chemotroph
d) Lithotroph

An Organism that produces CATALASE enzyme is protected from the harmful effects of ______?
a) singlet Oxygen
b) hydroxl radical
c) peroxide anion
d) superoxide radical

Which of the following OXIDIZING agents is sometimes produced during AEROBIC respiration?
A) singlet oxygen
B) peroxide anion
C) hydroxyl radical
D) molecular oxygen
E) superoxide radical

A microbe that grows only at the bottom of a tube of Thioglycollate medium is probably a(n)

An Organism that requires Chemical Nutrients which serve as  electron acceptors is a (n)

At temperature higher than the Maxium Growth temp for an organism
A) hydrogen bonds within molecules are broken
B) hydrogen bonds are broken and proteins are permanently denatured
C) proteins are permanently denatured
D) hydrogen bonds are broken, proteins are denatured, and membranes become too fluid
E) membrane become too fluid for proper function

Organisms that can grow with/without O2 present are?
A) Faculative anaerobes
B) Obligate anaerobes
C) Obligate aerobes
D) either Faculative anaerobes or Aerotolerant anaerobes
E) Aerotolerant anaerobes

Halophiles are found living in HIGH_____
conditions.

A microorganism found living under conditions of HIGH hydrostatic pressure is called a

Microaerophiles are microbes that grow best in low _______.

The _______ growth temp is the temp @ which an organism exhibits the highest growth rate.

You open a jar that has been in the refrigerator for a couple of weeks & find the contents do not look or smell Right.  What type of Microbe has been growing in your refrigerator?

Bacteria living in communities of microbes change the genes they are expressing in response to 
A) changes in local temperature
B) quorum-sensing molecules
C) decreasing oxygen
D) changes in hyrdostatic pressure
E) changes in pH

Microbial growth rates are controlled in a CHEMOSTAT by _________
A) controlling the amount of a limiting nutrient
B) controlling the amount of available oxygen
C) allowing waste products to accumulate
D) promoting biofilm formation
E) maintaining a constant temperature

MacConkey Agar plates represent _____ medium.
A) minimal
B) selective
C) differential
D) both a differential and a selctive

A devise that removes wastes & adds fresh Medium to bacterial cultures in order to Prolong the LOG Phase of a culture is called a _____________.

Bacterial BINARY FISSION results in __________ growth.

Which of the Following is an INDIRECT method for estimating the number of microbes in a sample
A) mpn
B) viable-plate counts
C) turbidity
D) coulter counter
E) membrane filtration

During which Growth Phase do antimicrobial drugs have the greatest inhibiting effect?
A) death phase
B) stationary phase
C) lag phase
D) log phase

Which of the following explains why honey can be stored at room temperature for years without spoiling?

The method of obtaining ISOLATED cultures that utilizes surface area to Physically Dilute specimens is called_________.

All of the Following are part of the Binary Fission EXCEPT????

Which of the Following is an approach to preventing the formation of BIOFILMS?
A) stimulating quorum sensing receptors
B) increasing Quorum Sensing
C) blocking the activity of carbohydrate catabolism
D) digesting matrix molecules
E) triggering the production of streamers

The_____ method provides an ESTIMATE of the CFU(Colony Forming Units) in a Sample.
A) Coulter counter
B) turbidity
C) viable plate-count
D) direct microscopic-count
E) streak -plate

Students in a microbiology lab are provided plates of Medium to use in their bacterial culturing.  The growth that can metabolize MANNOSE Sugar will result in the AGAR turning  YELLOW, while the AGAR color remains un-changed if the MANNOSE is NOT Metabolized.  The Plates contain__________Medium.
A) Differential
B) Transport
C) Selective
D) Defined
E) Reducing

Which of the Following Quantification Techniques can distinguish LIVING cells from DEAD Cells in a culture?
A) microscopic counts
B) metabolic activity
C) turbidity
D) a Coulter counter
E) dry weight

The Generation Time of bacterial cells is the SHORTEST during the _______ phase.
A) log
B) stationary
C) death
D) lag
E) longitudinal

When cells are Metabolically active but NOT dividing,they are in the ______phase.
A) lag
B) log
C) stationary
D) death
E) stationary

Metabolic activity is at MAX level in the ___ phase of growth.
A) death
B) lag
C) stationary
D) log
E) intermediate

Which of the following Methods is Best for counting Fecal bacteria from a stream to determine the safety of H20 for drinking?
A) Membrane Filtration
B) dry weight
C) turbidity
D) Viable Plate count

Organisms that Require Organic Sources of Carbon & Energy are called:_______

Reactions Catalyzed by Superoxide  Dismutases can produce the _____ radical.

A________ can measure changes in the Turbidity of a bacterial culture.
A) Spectrophometer
B) Counter
C) Cytometer

Alkalinophiles can survive in H20 up to pH.
A) 10
B) 11.5
C) 7.0

A sample placed into fresh medium is initially in the ______ phase of microbial growth in most instances.
A) Lag
B) Log
C) Stationary

T/F:  Thermoduric Mesophiles are often responsible for spoilage of improperly canned foods.
True False

T/F:  An Obligate ANAerobe can be cultured in a candle jar?
True False

T/F:  Reactions CATALYZED by SUPEROXIDE Dismutases can produce the Peroxide
True False

T/F:  BIOFILMS are the Natural states for the majority of bacteria in Nature.
True False

T/F:  Serial Dilution can be used in combination with Pour Plates as a Method for Isolating Pure cultures?
True False

T/F:  The GENERATION TIME of bacterial culture is determined by the Culture conditions.
True False

Creating conditions in the laboratory that promote the growth of some microbes while inhibiting the growth of others is called
A) reducing conditions
B) transport conditions
C) complex culturing
D) differential culturing
E) selective enrichment culturing