Chapter 9 objectives Flashcards
Quiz
Organisms called _____ live on or in the body of a host, and cause some degree of harm.
Pathogens
The toxic superoxide ion is converted to harmless oxygen by two enzymes,
superoxide dismutase and oxidase.
catalase and hydrogen peroxidases.
superoxide dismutase and catalase.
superoxide dismutase and catalase
An organism that can use gaseous oxygen in metabolism and has the enzymes to process toxic oxygen products is a/n
aerobe
E. coli bacteria that normally live in the human large intestines and produce vitamin K that the body uses would be best termed a _____ relationship.
mutualistic
An organic nutrient that cannot be synthesized by the organism and must be provided is called a/n
growth factor
In _____ conditions, the cell wall will help prevent the cell from bursting.
hypertonic
mesotonic
isotonic
hypotonic
hypotonic
The process by which a cell uses ATP to enclose a substance in its membrane, by forming a vacuole and engulfing it, is called:
endocytosis
Cultures of a bacterial species were incubated in a standard incubator, in an anaerobic jar, and in a candle jar. After incubation, there was moderate growth of cultures in the candle and anaerobic jars, but heavy growth of the culture in the incubator. This species is a/n
microaerophile.
aerobe.
anaerobe.
facultative anaerobe.
facultative anaerobe
Facilitated diffusion is limited by
carrier proteins in the membrane
A microorganism that has an optimum growth temperature of 37° C, but can survive short exposure to high temperatures is called a/n
thermoduric microbe
The phase of the bacterial growth curve in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing at an exponential rate, is the
lag phase
An organism with a temperature growth range of 45° C to 60° C would be called a/n
thermophile
Contractile vacuoles are
used to expel excess water from cells
Microorganisms require large quantities of ______ for use in cell structure and metabolism:
macronutrients
What is the difference between mutualism and synergism?
In a synergistic relationship the organisms cannot survive without each other.
In a synergistic relationship both organisms benefit, but in a mutualistic relationship both organisms are harmed.
In a mutualistic relationship the organisms are dependent upon each other.
in a mutualistic relationship the organisms are dependent upon each other
What type of media is used to demonstrate oxygen requirements of microbes?
thioglycollate
All of the following could find a location in or on body tissues suitable for growth except:
mesophiles.
anaerobes.
psychrophiles
psychrophiles
The milk that you bought from a grocery store a month ago got pushed to the back of the refrigerator hidden by other objects. Finding it a month later, unopened, you would like to now use it. Which statement is true?
The milk will still be fresh since it is a sterilized product.
The milk will still be fresh since the lactose sugar prevents the growth of any microorganisms.
Only thermoduric bacteria will be thriving in the milk.
Only thermoduric bacteria will be thriving in the milk.
The methanogens, producers of methane gas, require environments that:
are extremely cold.
are anaerobic with hydrogen gas and CO2.
have abundant oxygen and CO2.
are anaerobic with hydrogen gas and CO2.
An important mineral ion that is a component of chlorophyll, and stabilizer of membranes and ribosomes is:
potassium.
zinc.
magnesium.
magnesium.
The term facultative refers to:
the ability to exist in a wide range of conditions.
using chemicals for energy production.
using light for energy production.
the ability to exist in a wide range of conditions.
A microaerophile:
grows with or without oxygen.
needs normal atmospheric levels of oxygen.
requires a small amount of oxygen but won’t grow at normal atmospheric levels of oxygen.
requires a small amount of oxygen but won’t grow at normal atmospheric levels of oxygen.
A loopful of bacteria containing 1000 bacterial cells is inoculated into a nutrient broth and incubated. The culture was in lag phase for 10 minutes and then went into exponential log phase growth for 5 hours. The generation time for the bacterium is 15 minutes. Which equation set up is the correct one to determine how many cells at the end of the 5 hours of log phase growth.
1000 X 2(4)
1000 X 2(20)
1000 X 5 X 2 X 15
1000 X 40
1000 X 2(20)
Aerobic respiration is an example of:
photoautotrophy.
methanoheterophy.
chemoheterotrophy.
photoheterotrophy.
chemoheterotrophy.
Organisms that feed on dead organisms for nutrients are called:
phototrophs.
parasites.
autotrophs.
saprobes.
saprobes.
Nutrient absorption is mediated by the:
cell membrane.
peptidoglycan layer.
cell wall.
nuclear membrane.
cell membrane.
When microbes live independently but cooperate and share nutrients, it is called:
synergism.
symbiosis.
mutualism.
synergism.
The phase of the bacterial growth curve in which the rate of multiplication equals the rate of cell death is the:
stationary phase.
log phase.
death phase.
stationary phase.
After using the jelly on a sandwich, you close the jar and inadvertently place it on a room temperature shelf instead of in the refrigerator. When looking for the jelly a couple of weeks later and finding it on the shelf, you notice growth of a microorganism on the top of the jelly. What type of organism is likely to grow in this environment?
a fungus
a bacterium
a virus
a fungus
A bacterium is inoculated into a tube of nutrient broth and incubated. After incubation, it appears turbid throughout, top to bottom, with the most amount of turbidty at the very top. This bacterium would be called a:
aerotolerant
facultative anaerobe
psychrotroph
facultative anaerobe
Calcium is required for bacteria because it:
maintains cellular pH.
stabilizes the cell wall.
makes strong cell walls.
stabilizes the cell wall.
Microorganisms require small quantities of ______ for enzyme function and maintenance of protein structure:
trace elements
growth factors
macronutrients
trace elements
An organism that uses CO2 for its carbon needs and sunlight for its energy needs would be called a:
saprobe.
heterotroph.
photoautotroph.
photoautotroph.
Which of the following is not a major element of a microbial cell?
copper
nitrogen
oxygen
copper
Which of the following environmental conditions would be inappropriate for isolation of extremophilic microorganisms?
a yogurt container, pH 4.7
seawater, NaCl content of 3.5%
a compost pile with decaying vegetables and grass, temperature of 55 degree celsius
a compost pile with decaying vegetables and grass, temperature of 55 degree celsius
An organism that can exist in both oxygen and oxygen-free environments is a/n:
facultative anaerobe.
obligate anaerobe.
obligate aerobe.
facultative anaerobe.
The term obligate refers to:
the ability to exist in a wide range of conditions.
using light for energy production.
existing in a very narrow niche.
existing in a very narrow niche
The movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy is called:
facilitated diffusion.
diffusion.
active transport.
active transport.
Cultures of a bacterial species were incubated on the shelf of a refrigerator (5°c), out on a lab bench top (22°c), on the shelf of a 37° C incubator, and on the shelf of a 50° C incubator. After incubation, there was no growth at 37° C and 50° C, slight growth in the refrigerator, and abundant growth on the lab bench top. What term could be used for this species?
mesophile
halophile
psychrotroph
psychrotroph
When microbes are in a close nutritional relationship, and one benefits but the other is not harmed, it is called:
synergism.
mutualism.
commensalism.
commensalism.
An organism that cannot grow without oxygen is a/n:
obligate anaerobe.
facultative anaerobe.
obligate aerobe.
obligate aerobe.
When whole cells or large molecules in solution are engulfed by a cell, this endocytosis is specifically termed:
exocytosis.
pinocytosis.
phagocytosis.
phagocytosis.
A microorganism that does not have catalase or superoxide dismutase would find it difficult to live in an environment with:
carbon dioxide.
high salt.
oxygen.
oxygen.
Which of the following microorganisms would find hypotonic conditions most detrimental?
bacteria
fungi
protozoa
protozoa
You inoculate the bacterium into 3 tubes of nutrient broth medium containing salt–0.5% NaCl, 5% NaCl, and 15% NaCl. After incubation, you notice that the organism is growing very well in the 15%, and somewhat in the 5%. There is no growth in the third tube. This organism would be called:
barophilic
osmophobic
halophilic
halophilic
An organism that grows slowly in the cold but has an optimum growth temperature of 32° C is called a/n:
psychrophile.
extremophile.
facultative psychrophile.
facultative psychrophile.
Which of the following require the cell to use ATP?
facilitated diffusion
osmosis
diffusion
endocytosis
endocytosis