Microbiology chapter 7 Flashcards

Which set of four elements makes up the largest portion of cells by dry weight?
A) carbon, sulfur, potassium, oxygen
B) oxygen, nitrogen, phosphorus, hydrogen
C) carbon, hydrogen, oxygen, nitrogen
D) nitrogen, carbon, sulfur, potassium

Any substance, whether in elemental or molecular form, that must be provided to an organism is called a(n)
A) ionic nutrient.
B) essential nutrient.
C) micronutrient.
D) trace element.

A micronutrient can also be called
A) a trace element.
B) a macronutrient.
C) an elemental reservoir.
D)

Microbial cell cytoplasm is composed mostly of
A) water and protein.
B) macronutrients in elemental form.
C) salts and glucose.
D) peptidoglycan.

An autotroph
A) uses inorganic carbon dioxide as its carbon source.
B) uses organic carbon as its carbon source.
C)

Nitrogen is vital to microbial growth. It is obtained from organic or inorganic sources to make
A) amino acids.
B) proteins.
C) nucleotides.
D) all of the above.

A ____________ metabolizes the organic matter of dead organisms.
A) parasite
B) saprobe
C) photoautotroph
D) all of the above

Extracellular digestion in bacteria and fungi
A) aids endocytosis.
B) results in exocytosis.
C) facilitates transport of nutrients in.
D) results in transport of wastes out.

When the environment is equal in solute concentration to the cell's internal environment then there is no net change in cell volume. This indicates a(n) ____________ solution around the cell.
A) hypotonic
B) hypertonic
C) isotonic
D) barometric

Cell walls are useful for structural integrity as well as to keep a cell from bursting in a(an) solution.
A) hypotonic
B) isotonic
C) hypertonic
D) barometric

The majority of medically significant microorganisms are
A) thermophiles.
B) mesophiles.
C) psychrophiles.
D) halophiles.

An organism that is capable of living without oxygen if necessary is termed a(n)
A) aerobe.
B) facultative anaerobe.
C) obligate anaerobe.
D) aerotolerant anaerobe.

Most cultured bacteria tend to multiply by
A) binary fission.
B) budding.
C) fragmentation.
D) sexual reproduction.

During this phase of growth, newly inoculated cells require a period of adjustment, enlargement, and synthesis.
A) death phase
B) exponential growth phase
C) stationary growth phase
D) lag phase

The duration of each bacterial division is called the generation or
A) exponential time.
B) viable growth.
C) doubling time.
D) growth curve.

Assuming I had a single bacterium that could undergo binary fission every 30 minutes, how many bacteria would I have at the end of 7 hours?
A) 72
B) 730
C) 230
D) 214

Cell numbers can be counted directly by all of the following EXCEPT
A) microscope counting chamber.
B) Coulter counter.
C) flow cytometer.
D) turbidity.

The stationary growth phase in a bacterial growth chart is due to all of the following EXCEPT
A) depletion of nutrients in the culture.
B) increased density of cells.
C) a period of adjustment to growing conditions.
D) accumulation of wastes and byproducts.

The optimum pH for most culturable microbes ranges between
A) 3-5.
B) 5-7.
C) 6-8.
D) 8-10.

Microbes in most environments form ecological associations with other organisms. The term for a symbiotic relationship beneficial to both partners is termed a
A) commensalism.
B) mutualism.
C) parasitism.
D) competition.

Microorganisms which exist under high pressure are called
A) thermophiles.
B) barophiles.
C) psychrophiles.
D) halophiles.

Phagocytosis and pinocytosis are forms of
A) osmosis.
B) diffusion.
C) passive transport.
D) active transport.

The word root troph means
A) love
B) heat
C) food/feeding
D) self

The word root phile means
A) love
B) heat
C) food/feeding
D) self

The word root thermo means
A) love
B) heat
C) food/feeding
D) self

The word root auto means
A) other
B) self
C) light
D) love

The word root hetero means
A) other
B) self
C) light
D) love

The word root photo means
A) other
B) self
C) light
D) love

A microbiologist inoculates staphylococcus aureus into a culture medium. following incubation, both staphylococcus aureus and staphylococcus epidermis are determined to be growing in this culture. what is the most likely explanation?

A) The culture medium was differential

B) The microbiologist used too inoculum

C) The culture medium was selective

D) The culture was contaminated

Agar is important component of media because

A) agar prevents contamination

B) Bacteria require agar as a source of carbon

C) Agar inhibits mold growth

D) Agar provides a solid surface for bacterial growth

the term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is

A) isolation

B) Inoculation

C) infection

D) Contamination

A pure culture contains

A) only bacteria

B) A variety of species from the same genus

C) Microbes from a single source

D) Only one identified species of microorganism

A nutrient medium that contains at least one ingredient that is not chemically defined is termed

A) Enriched

B) Synthetic

C) Complex

D) Reducing

An organic nutrient that cannot be synthesized by the organism and must be provided is called a

A) Growth factor

B) Compound

C) Element

D) Macronutrient

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

A) Oxygen

B) Hydrogen

C) Copper

D) Carbon

Microorganism require large quantities of_____ for use in cell structure and metabolism

A) Macronutrients

B) Electrolytes

C) Trace elements

D) Water

An organism that use CO2 for its carbon needs and sunlight for its energy needs would be called a____

A) Photoautotroph

B) Heterotroph

C) Chemo heterotroph

D) Saprobe

Diffusion of water through a semipermeable membrane is called

A) Facilitated diffusion

B) Osmosis

C) Active transport

D) Endocytosis