CH. 7

Which term describes microorganisms that thrive under high hydrostatic pressure? A. halophiles B. mesophiles C. barophiles D. thermophiles

C

Which element plays a key role in maintaining the pH of cells?

hydrogen

The most common gas in Earth's atmosphere is _______

nitrogen

Assuming that you begin with a single bacterial cell which has a doubling time of 20 min, you would find ____ bacterial cells after one hour of growth

8

Biofilms infections are often chronic b/c ___________ A. antibiotic treatments are often ineffective B. multiple organisms are responsible for the infection C. the hosts are immunocompromised

A

Choose the temp range of psychrophilic microorganisms A. 15 to -20 degrees C B. 45 - 80 degrees C C. 10-50 degrees C D. 80-110 degrees C

A

During which phase of growth are microbes esp vulnerable to antimicrobial agents and disinfectants? A. exponential phase B. lag phase C. stationary phase

A

Saprobes are decomposers of plant and animal matter, and cannot engulf these large food particles. As a consequence, they excrete enzymes that function to ___________ A. degrade the food to smaller molecules that can be transported into the cell B. harness the energy in ATP to move the food particles into the cell C. generate pores in the cell wall to allow the passage of large food particles

A

Where would a thermophilic microorganism be found? A. in a natural hot springs B. in the ocean C. on refrigerated food D. in a patient with a fever

A

Which automated device can electronically scan a culture as it flows through a pipette to determine the total number of cells present, though it cannot distinguish which are alive or dead? A. coulter counter B. flow cytometer C. biosensor D. PCR machine

A

Which is not among the 6 most essential elements required for microbial growth? A. sodium B. phosphorus C. sulfur

A

Which of the following organisms does not utilize oxygen regardless of availability? A. aerotolerant anaerobe B. facultative anaerobe C. microaerophile

A

Which phase of bacterial growth in considered to be first? A. lag B. death C. exponential D. stationary

A

Which term is used to describe the coordinated action btw two microorganisms or drugs that results in a heightened response or greater effectiveness? A. synergism B. symbiosis C. antagonism

A

Methanogens are _________. Select all that apply A. archaea B. producers of carbon dioxide and hydrogen C. chemoorganic autotrophs D. found most commonly in aerobic environments

A, C

Which of the following describe how biofilms become resistant to many antibiotics? Select all that apply A. some biofilm microbes can produce protective compounds to stop antibiotic activity and thereby protect the entire biofilm B. the biofilm becomes too large to be phagocytized by immune cells C. peripheral microbes die and protect amore internal microbes from harm

A, C

From which environment would you most likely observe growth of psychrophilic microorganisms? A. outside air in summer months B. frozen food C. water from a hot tub

B

The organism with the shortest generation time (fastest growth) would be ____________ A. a psychrophile growing t 37 degrees C B. a mesophile growing at 37 degrees C C. a thermophile growing at 37 degrees C

B

To measure the generation time of an organism, it should be in _______ phase? A. stationary B. exponential C. death D. lag

B

Which condition is not optimal for survival of an anaerobic pathogen w/in a human host? A. 35 degrees C B. 10% salt C. a pH 7 D. poor oxygen availability

B

Which term best describes the association btw a human host and the normal microbiota that aids in digestion? A. parasitic B. mutualistic C. commensal

B

Put the following phases in order for a normal bacterial growth curve, beginning with the first at the top A. stationary B. lag C. exponential D. death

B, C, A, D

Cellular growth can be visualized by: A. a decrease in nitrogen levels B. an increase in cell size C. an increase in cell # D. an increase in cellular components E. formation of multiple nuclei

B, C, D

Which of the following infections regularly involve biofilms? Select all that apply A. AIDS B. wound infections C. ear infections D. athlete's foot E. lung infections in cystic fibrosis patients

B, C, E

Which 3 of the following contain nitrogen? A. carbs B. proteins C. fats D. RNA E. DNA

B, D, E

Assuming you start with just one microbe and it could divide every 30 minutes, how many microbes would you have after 2 hours? A. 32 B. 8 C. 16 D. 4

C

Which instrument is used to determine relative cell density based on turbidity of a culture? A. PCR B. counting chamber C. spectrophotometer D. coulter counter

C

Which of the following compounds require phosphorus as a component? A. proteins B. lipids C. nucleic acids D. carbohydrates

C

Which of the following is false regarding a facultative anaerobe? A. prefers using oxygen if present B. produces energy by respiration or fermentation pathways C. the electron transport system is non-functional D. can grow in the absence of oxygen

C

Which of the following is not a good example of a chemoheterotroph? A. fungi B. humans C. plants D. bacteia

C

Which of the following is not among the 6 most essential elements required for microbial growth? A. nitrogen B. carbon C. calcium

C

Which process can be used to quantify cell #s in a sample without culturing the actual microbe? A. streak plating B. photosynthesis C. PCR D. gram staining

C

Put the stages of binary fission in the correct order: A. Septum is completely formed and cell membrane begins to patch itself B. septum begins to form; chromosomes are affixed to cytoskeleton and separated into the forming cells; components are randomly divided C. cell wall membrane, and overall volume are enlarged; chromosome is duplicated D. daughter cells are divided

C, B, A, D

Choose the temperature range of mesophilic microorganisms A. 45 to 80 degrees C B. -15 to 20 degrees C C. 80 to 110 degrees C D. 10 to 50 degrees C

D

Some microbes produce _____________ to protect themselves against damaging electromagnetic radiation A. free radicals B. antibiotics C. catalase D. pigments

D

What specific is used to describe the production of antibiotics from normal microbiota that leads to the protection of our bodies? A. natural resistance B. antagonism C. normal resistance D. antibiosis

D

When gas has the greatest impact on microbial growth and is a powerful oxidizing agent that exists in many forms that can be toxic to microbes? A. carbon dioxide B. sulfur C. nitrogen D. oxygen

D

Which of the following can be measured or analyzes in an uncultured environmental or tissue sample in order to quantify cell #s present? A. mitochondria B. ribosomes C. nuclei D. ATP

D

Which of the following characterizes the lag phase of a normal bacterial growth curve? A. exponential decline in cell numbers B. depletion of nutrients and build up of waste C. logarithmic cell division D. little increase in cell #s

D

Which of the following is not part of binary fission? A. septum formation completes and cell membrane patches B. daughter cell separate C. septum begins to form and chromosomes are pulled to opposite sides of the cell D. chromosomes line up so that crossing over occurs E. cell components enlarge and bacterial chromosome is duplicated

D

Which term describes the lowest temp at which a microbe can grow? A. maximum temp B. optimum temp C. low point range D. minimum temp

D

Nitrogen sources must first be converted to ammonia, the only form of nitrogen that can be directly combined with carbon to synthesize _________ _______

amino acids

Nitrogen sources must first be converted to ________, the only form of nitrogen that can be directly combined with carbon to synthesize amino acids and other compounds

ammonia

Tetanus and gangrene are deep tissue infections mainly associated with which type of bacteria?

anaerobic

When our normal microbiota produce which help protect us from pathogens, this is specifically called __________

antibiosis

A(n) ___________ is an organism that requires only inorganic nutrients and carbon dioxide as a sole carbon source

autotroph

bacteria reproduce by _________ fission

binary

Some microbes live in mixed communities attaches to a surface and are fairly resistant to antibiotics. These formations are called __________ and often grow on materials such as catheters

biofilms

The element _________ is represented by the letter C in CHONPS

carbon

A microbe's nutritional type is determined by its source of ________ and ________

carbon and energy

___________ is a type of symbiotic relationship btw 2 organisms in which one species derives benefit without harming the other

commensalism

enumeration of bacteria can be achieved by the __________ cell count, in which a cell suspension in a chamber is viewed under the microscope

direct

T/F: Photosynthetic microbes are not damaged by electromagnetic radiation

false

Which term describes the length of time of a microbial species needs to divide?

generation time

A __________ curve is a graphical representation of the change in pop size over time

growth

________ phase follows inoculation and is when the pop appears not to be growing

lag

Which microorganism uses inorganic chemicals for energy and carbon dioxide for carbon?

lithoautotroph

A(n) _________ is an aerobic bacterium that requires oxygen oxygen at a concentration less than that in the atmosphere

microaerophile

What name is given to compounds such as manganese and zinc which are needed by cells in very small quantities?

micronutrients

____________ is a type of symbiotic relationship btw 2 organisms in which both species benefit

mutualism

Because they are unable to grow outside of a living host, the leprosy bacillus and syphillis spirochete are examples of __________ parasites

obligate

What term is used to describe the best temp to support a microbe's growth?

optimal temp

A(n) ________ is a microorganism that thrives in any hypertonic medium

osmophile

Which compound of peroxides is lethal to anaerobic microbes?

oxygen

Which gas is found at about 20% of Earth's atmosphere?

oxygen

Many freshwater lakes in the US are seeing massive blooms of algae in summer. These photosynthetic organisms grow on CO2 and N2 (gases) for their carbon and nitrogen sources, and were previously limited in their ability to grow because of a lack of ______ in the lakes.

phosphorus

Which term is used to describe organisms that use the sun's light to directly power their metabolic pathways?

phototrophs

All bacteria can be divided by their energy sources as ________ or _________

phototrophs; chemotrophs

two sulfur-requiring precursor molecules are cysteine and methionine. These are needed to synthesize _________

proteins

The ability of some bacteria to detect the #s of often similar species of bacteria within a given area is called ________ _________

quorum sensing

__________ is a close association btw individual from two species that may be helpful, harmful, or neither to both members

symbiotic

Microorganisms that prefer hot environments in the range of 45 to 80 degrees C are called ________- philes

thermo

What term is used to describe microbes which can survive fairly high temps but can only metabolize and reproduces at lower temps?

thermoduric

T/F: Nutrition is the acquisition of chemical substances by organisms for use as an energy source or as building blocks of cellular structures

true

T/F: ions such as calcium and iron are important nutrients for microbes to acquire from their environments

true