Micro chapter 7 quiz

An organism that can not grow without oxygen is a(n)

obligate aerobe

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

The production of antibiotics is a form of antagonism called

antibiosis

Archea as a group are not pathogens. This is because

Mammalian hosts do not meet their environmental requirements

Most of the dry weight of a microbial cell is from

organic compounds

An organism that uses CO2 for its carbon needs and sunlight for its energy needs would be called a/an

photoautotroph

In the viable plate count method, a measured sample of a culture is evenly spread across an agar surface and incubated. Each _____ represents one _____ from the sample.

colony cell

Growth factors

Cannot be synthesized by the organism

Organisms that feed on dead organisms for nutrients are called

saprobes

An organism that grows slowly in the cold but has an optimum growth temperature of 32° C is called a(n)

facultative psycrophile

A barophile would grow best in

deep oceans

True or False: Most microorganisms on earth can only live and survive in habitats that are similar to human body conditions.

false

A microorganism that has an optimum growth temperature of 37° C, but can survive short exposure to high temperatures is called a(n)

thermoduric

True of False: Facilitated diffusion and active transport require a carrier protein to mediate the movement across the plasma membrane.

true

True or False: Bacteria have an average generation time of 24 hours.

false

Trueor False: Saprobes do not need a carbon source for growth and metabolism.

false

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

phagocytosis

True or False:

Transverse binary fission results in 4 daughter cells from 1 parent cell.

false

The term facultative refers to

The ability to exist in a wide range of conditions

Contractile vacuoles are

used to expel excess water from cells

Mediated transport of polar molecules and ions across the plasma membrane utilizes a _____ _____ that will bind to the substance effecting a conformational change that allows movement across the membrane.

protein carrier

Cultures of a bacterial species were incubated on the shelf of a refrigerator, out on a lab bench top, 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 out on the bench top and abundant growth at refrigeration. What term could be used for this species?

psychrophile

A microaerophile

Requires a small amount of oxygen but won’t grow at normal atmospheric levels

True or False: Phosphorus is one of the major elements needed in larger quantities by microorganisms.

true

An organism with a temperature growth range of 45° C to 60° C would be called a(n)

thermophile

The term autotroph refers to an organism that:

Uses CO2 for its carbon source

True or False: Whether an organism is an autotroph or heterotroph depends on its source of nitrogen.

false

True or False: Whether an organism is an autotroph or heterotroph depends on its source of nitrogen.

false

Which of the following microorganisms would find hypotonic conditions most detrimental?

protozoa

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

pathogens

Human pathogens fall into the group

mesophiles

The term heterotroph refers to an organism that

must obtain organic comound for its cabon needs

In _____ conditions, the cell wall will help prevent the cell from bursting.

hypotonic

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

psychrophiles

An organism that can exist in both oxygen and oxygen-less environments is a(n)

Facultative anaerobe

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

oxygen

Halobacteria regulate osmotic pressure by

Absorbing salt from the environment

Calcium is required for bacteria because

It stabilizes the cell wall

A change in one partner in a close relationship that leads to a change in the other partner is

coevolution

A halophile would grow best in

salt lakes

Aerobic respiration is an example of

Chemoheterotrophy

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

Facilitated diffusion

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

synergism

True or False: A saprobe with a cell wall will utilize extracellular digestion.

true

Facilitated diffusion is limited by

Carrier proteins in the membrane

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

commensalism

True or False: In a commensal relationship, the commensal benefits but the cohabitant is neither harmed nor benefited.

true

True or False: A Coulter counter can count viable cells as well as determine the size.

false

True or False: The direct cell count, using a cytometer, can calculate viable cell numbers from a sample.

false

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

diffusion

True or False: Bacterial biofilms stimulate the immune system differently than planktonic bacteria.

true

The methanogens, producers of methane gas, require environments that

Are anaerobic with hydrogen gas and CO2

The E. coli that normally live in the human large intestines and produce vitamin K that the body uses would be best termed a _____ relationship.

mutualistic

True or False: Inorganic nitrogen must be converted to ammonia to be used by a cell.

true

True or False:Anaerobes can be cultured in a CO2 environment.

true

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

copper

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

lag phase

True or False: Lithoautotrophs use inorganic nutrients for carbon and energy sources.

true

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

active transport

True or False: Whether an organism is a phototroph or a chemotroph depends on its source of energy.

true

The type of photosynthesis that does not produce oxygen

occurs in purple or green sulfur bacteria

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

trace element

The term phototroph refers to an organism that

Gets energy from sunlight

True or False: The degree of turbidity in a broth culture correlates to the amount of cell growth.

true

Diffusion of water through a semi permeable membrane is called

osmosis

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

shrivel

True or False: A closed culture system is used to determine a population growth curve.

true

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

Superoxide dismutase and catalase

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

growth factor

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

generation time

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

macronutrient

The term obligate refers to

Existing in a very narrow niche

Nutrient absorption is mediated by the

cell membrane

What compound has the highest concentration in a cell?

H2O

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

endocytosis

An organism that cannot tolerate an oxygen environment is a(n)

obligate anaerobe

What type of media is used to demonstrate oxygen requirements of microbes?

thioglycollate

True or False: The time that it takes for a freshly inoculated agar culture to develop visible colonies is principally governed by that species’ generation time.

true

The term chemotroph refers to an organism that

Gets energy by oxidizing chemical compounds

True or False: The majority of microbes live and grow in habitats between pH 7 and 9.

false

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

stationary phase

True or False: After binary fission, daughter cells will differ genetically.

false

Which of the following require the cell to use ATP?

endocytosis

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

log phase

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

iron

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

magnesium

True or False:

Planktonic bacteria are more susceptible to antibiotics as compared to biofilm microorganisms.

true

Cultures of a bacterial species were incubated out on the incubator shelf, 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 on the incubator shelf. This species is a/an

Facultative anaerobe

Microorganisms that live in severe habitats, such as very hot, acidic or salty environments, are called

Extremophiles

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

Aerobe

isotonic conditions means that

the environment is equal in solute concentration to the cell’s internal environment.

passive transport definition

the cell does not expend extra energy for them to function

hypertonic conditions

environment is exposed to a higher solute concentration than its cytoplasm

hypotonic conditions

the solute concentration of the external environment is lower than that of the cell’s internal environment

plasmolysis defintion

shrinkage of the protoplast away from the wall

true or false: norganic nitrogen must be converted to ammonia to be used by a cell.

true