Microbiology Exam 3

Microorganisms require large quantities of this nutrient for use in cell structure and metabolism:

Macronutrient

Microorganisms require small quantities of this nutrient for enzyme function and maintenance of protein structure

trace element

What compound has the highest concentration in a cell?

H2O

Most of the dry weight of a microbial cell is from

organic compounds

Which of the following is not a major element of a microbial cell?

A. copper

B. carbon

C. hydrogen

D. nitrogen

E. oxygen

A. copper

An important mineral ion of the cytochrome pigments of cellular respiration is

A. iron

B. zinc

C. calcium

D. magnesium

E. potassium

A. iron

An important mineral ion that is a component of chlorplasts and stabilizer of membranes and ribosomes is

magnesium

The term autotroph refers to an organism that

uses CO2 for its carbon source

The term photoheterotroph refers to an organism that

gets energy from sunlight

The term photoheterotroph refers to an organism that

stabilizes the cell wall

An organism that uses CO2 for its carbon needs would be called a(n)

autotroph

The term photoautotroph refers to an organism that

gets energy from sunlight

The term chemoheterotroph refers to an organism that

gets energy by oxidizing chemical compounds

Organisms that feed on dead organisms for nutrients are called

saprobes

Archaea, as a group, are not pathogens. This is because

mammalian hosts do not meet their environmental requirements

aerobic respiration is an example of

chemoheterotrophy

Organisms called ________ live on or in the body of a host and cause some degree of harm

parasites

The term “obligate” refers to

existing in a very narrow niche

The term facultative refers to

The ability to exist in a wide range of conditions

The movement of molecules from an area of high concentration to an area of lower concentration is called

diffusion

Diffusion of water through a semipermeable membrane is called

Osmosis

The movement of substances from a lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy is called

active transport

The movement of substances from a higher to lower concentration across a semipermeable membrane that must have a specific protein carrier but no energy expenditure is called

facilitated diffusion

The use of energy by a cell to enclose a substance in its membrane by forming a vacuole and engulfing it is called

endocytosis

Bacteria living in a freshwater stream that are moved to salty seawater would

shrivel

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Which of the following require the cell to use ATP?

a. facilitated diffusion

b. diffusion

c. endocytosis

d. osmosis

e. none of the above

c. endocytosis

Nutrient absorption is mediated by the

cell membrane

Facilitated diffusion is limited by

carrier proteins in the membrane

When whole cells or large molecules in solution are engulfed by a cell, this endocytosis is specifically termed

phagocytosis

In ______ conditions, the cell wall will help prevent the cell from bursting

hypotonic

An organism that grows slowly in the cold but has an optimum growth temperature of 25 degrees Celcius is called a

psychrotroph

An organism with a temperature growth range of 45 degrees Celcius to 60 degrees celcius would be called a

thermophile

Human pathogens fall into the group

mesophiles

All of the following could find a location in or on body tissues suitable for growth except

A. psychrophiles

B. anaerobes

C. facultative anaerobes

D. mesophiles

E. capnophiles

A. psychrophiles

A microorganism that does not have catalase or superoxide would find it difficult to live in an environment with

oxygen

A microaerophile

requires a small amount of oxygen but wont grow at normal atmospheric levels

The toxic superoxide ion is converted to harmless oxygen by two enzymes

superoxide dismutase and catalase

An organism that can use gaseous oxygen in metabolism and has the enzymes to process toxic oxygen products is a

aerobe

An organism that can exist in both oxygen and oxygenless environments is a

facultative anaerobe

An organism that cannot tolerate an oxygen environment is a

obligate anaerobe

An organism that cannot grow without oxygen is a

obligate aerobe

A halophile would grow best in

A. acid pools

B. freshwater ponds

C. hot geyser springs

D. arid, desert soil

E. salt lakes

E. salt lakes

A barophile would grow best in

A. acid pools

B. the deep oceans

C. hot geyser springs

D. arid, desert soil

E. salt lakes

B. the deep oceans

The E. coli that normally live in the human large intestines and produce vitamin K for the body to use would best be termed a ______ relationship

mutualistic

The production of antibodies is a form of antagonism called

antibiosis

When microbes live independently but cooperate and share nutrients, it is called

synergism

When microbes are in a close nutritional relationship, and one benefits but the other is not harmed, it is called

commensalism

The time interval from parent cell to two new daughter cells is called the

generation time

The phase of the bacterial growth curve in which the rate of multiplication equals the rate of cell death is the

stationary phase

The phase of the bacterial growth in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing, is the

lag phase

The phase of the bacterial growth curve that shows the maximum rate of cell division is the

exponential (log) phase

When it is important to count the number of cells, determine cell size, and differentiate between dead and live cells, a ____ is used

flow cytometer

TRUE OR FALSE: phosphorus is one of the major elements needed in larger quantities by microorganisms

TRUE

TRUE OR FALSE: Most microorganisms on earth can only live and survive in habitats that are similar to human body conditions

FALSE

TRUE OR FALSE: Whether an organism is a phototroph or a chemotroph depends on its source of energy

TRUE

TRUE OR FALSE: Saprobes do not need a carbon source for growth and metabolism

FALSE

TRUE OR FALSE: Lithoautotrophs use inorganic nutrients for carbon and energy sources

TRUE

TRUE OR FALSE: Facilitated diffusion and active transport require a carrier protein to mediate the movement across the plasma membrane

TRUE

TRUE OR FALSE: In a commensal relationship, the commensal benefits but the cohabitant is neither harmed nor benefited.

TRUE

TRUE OR FALSE: Anaerobes can be cultured in a CO2 environment

TRUE

TRUE OR FALSE: The majority of microbes live an grow in habitats between pH 7 and 9

FALSE

TRUE OR FALSE: Bacteria have an average generation time of 24 hours

FALSE

TRUE OR FALSE: The time that it takes for a freshly inoculated agar culture to develop visible colonies is principally governed by the generation time of the inoculated species

TRUE

TRUE OR FALSE: Binary fission results in four daughter cells from one parent cell

FALSE

TRUE OR FALSE: After binary fission, daughter cells will differ genetically

FALSE

TRUE OR FALSE: A closed culture system is used to determine a population growth curve

TRUE

TRUE OR FALSE: The degree of turbidity in a culture correlates to the amount of cell growth

TRUE

TRUE OR FALSE: The direct cell count, using a cytometer, can calculate viable cell numbers from a sample

FALSE

TRUE OR FALSE:A Coulter counter can count viable cells as well as determine the size

FALSE

TRUE OR FALSE: Bacterial biofilms stimulate the immune system differently than free (planktonic) bacteria

TRUE

Viruses have all the following except

A. definite shape

B. metabolism

C. genes

D. the ability to infect host cells

E. ultramicroscopic size

metabolism

Who developed a rabies vaccine by separating bacteria from virus using a filter?

Pasteur

Host cells of viruses include

A. humans and other animals

B. plants and fungi

C. bacteria

D. protozoa and algae

E. all of the above

E. all of the above

Viruses ______

A. cannot be seen in a light microscope

B. are prokaryotic

C. contain 70S ribosomes

D. undergo binary fission

E. All of the choice are correct

A. cannot be seen in a light microscope

Virus capsids are made from subunits called ______

capsomeres

Helical and icosahedral are terms used to describe the shapes of a virus _______

capsid

A ______ is the protein shell around the nucleic acid core of a virus

capsid

One of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a _______ capsid

icosahedral

A naked virus has only a

nucleocapsid

Which of the following is not a typical capsid shape?

A. Tetrahedral

B. Complex

C. Helical

D. Icosahedron

E. All of the choices are capsid shapes

A. Tetrahedral

All of the following pertain to virus envelopes except ______

A. gained as a virus leaves the host cell membrane

B. are comprised primarily of lipids

C. contain special virus proteins

D. help the virus particle attach to host cells

E. are located between the capsid and nucleic acid

E. are located between the capsid and nucleic acid

Viral spikes ________

A. are present on all viruses

B. protrude from the envelope

C. block attachment between virus and host

D. are derived from host proteins

E. All of the above

B. protrude from the envelope

The core of every virus particle always contains

either DNA or RNA

Which of the following is not associated with every virus?

A. envelope

B. Capsomeres

C. Capsid

D. Nucleic acid

E. Genome

A. envelope

Viral nucleic acids include which of the following?

A. double stranded DNA

B. single stranded DNA

C. double stranded RNA

D. single stranded RNA

E. All of the above

E. All of the above

Reverse transcriptase synthesizes

DNA from RNA

A negative-sense RNA virus ______

A. is ready for immediate translation

B. must synthesize a negative RNA copy of its genome

C. must synthesize a positive RNA copy of its genome

D. is a special form of tRNA used by viruses

E. always codes for RNA polymerase

C. must synthesize a positive RNA copy of its genome

Viruses with ______ -sense RNA contain the correct message for translation, while viruses with ______ - sense RNA must first be converted into a correct message

positive; negative

Viruses acquire envelopes around their nucleocapsids during ________

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release

In general, most DNA viruses multiply in the host cell’s _____ while most RNA viruses multiply in the host cell’s _____

nucleus; cytoplasm

Host range is limited by

type of host cell receptors on cell membrane

Oncoviruses include all the following except

A. hepatitis B virus

B. measles virus

C. papillomavirus

D. HTLV I

E. Epstein-Barr Virus

B. measles virus

Which of the following is a type of cytopathic effect?

A. Inclusions in the nucleus

B. multinucleated giant cells

C. inclusions in the cytoplasm

D. Cells change shape

E. All of the above

E. All of the above

The envelope of enveloped viruses ______

is obtained by viral budding or exocytosis

Viruses attach to their hosts via

host glycoproteins

Viral tissue specificities are called

tropisms

The process of dissolving the envelope and capsid to release the viral nucleic acid is

uncoating

Which of the following occurs during assembly of an enveloped virus?

A. nucleocapsid is formed

B. new viral nucleic acid is formed

C. viral spikes insert in host cell membrane

D. a nucleocapsid is formed and viral spikes insert in host cell membrane

E. All of the above

D. a nucleocapsid is formed and viral spikes insert in host cell membrane

Mammalian viruses capable of starting tumors are

oncoviruses

Persistent viruses that can reactivate periodically are _____

chronic latent viruses