microbes hw

The compound that is an organic base containing chlorine and two phenolic rings, and is used increasingly for wound degerming, neonatal washes, hand scrubbing, and prepping surgical skin sites is _______.

chlorhexidine

Which of the following is true regarding the use of osmotic pressure as an antimicrobial agent?

exposing a microbe to a hypertonic environment draws water out of the cell, causing plasmolysis

Which of the following microbial forms has the highest resistance to physical and chemical controls?

bacterial endospores

Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is _______.

degermation

_____ is a halogen used in gaseous and liquid form for large scale disinfection of drinking water and sewage.

chlorine

Vials of microorganisms that undergo the freeze-drying process, called _____, will remain preserved and viable for years.

lyophilization

Which of the following is not a factor that affects germicidal activity?

all the choices are factors

(strength of the germicide, material being treated, length of exposure, microorganism being treated)

Which of the following represents the use of osmotic pressure as a microbial control method?

salting of meat

All of the following pertain to hypochlorites except _______.

they are found in iodophors

What instrument is most effective for pressure-temperature sterilization?

autoclave

Hydrogen peroxide is _______.

all the choices are correct

(fungicida, virucidal, sporicidal, bactericidal)

The chemical agent/s that produce/s highly reactive hydroxyl-free radicals and also decomposes to O2 gas is _______.

hydrogen peroxide

The use of a physical or chemical process to destroy vegetative pathogens on inanimate objects is ______.

disinfection

All of the following are phenols or phenolics except ______.

zephiran

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is _______.

antisepsis

The alcohol wipe used on a patient's skin before an injection is an example of ______.

antisepsis

The method of removing vegetative microbial life forms and debris to reduce contamination to safe levels is termed ______.

sanitization

Removal of moisture by dehydration is called ______.

desiccation

_____ is a control method that removes microorganisms rather than inhibiting or killing them.

filtration

Physical agents for controlling microbial growth include all of the following except ______.

hydrogen peroxide

Each of the following is a target of antimicrobial agents except ______.

cytoplasm

The process that destroys or removes all microorganisms and microbial forms, including bacterial endospores, on inanimate objects is ______.

sterilization

Which of the following methods of microbial control is mismatched?

pickling eggs - osmotic pressure

Which of the following types of control agents would be used to achieve sterility?

sporicide

Disinfection of beverages such as apple juice, milk, and wine is optimally achieved by ______.

pasteurization

Cultures of a bacterial strain were incubated in a refrigerator (5°C), on a lab bench (22°C), in a 37°C incubator, and in 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. Which term best describes this organism?

psychrotolerant

Human pathogens fall into the group called ______.

mesophiles

Cultures of a bacterial strain 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/an ______.

facultative anaerobe

Termites are insects that require the protozoan Trichonympha in their gut to synthesize the enzyme cellulase to degrade the cellulose in wood. The protozoan uses the end products of the cellulose breakdown (glucose). This is a/an ______ relationship.

mutualistic

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

stationary phase

Microbes in a biofilm use quorum sensing to _______.

assess the size of a particular microbial population

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

thermoduric microbe

An organism that grows slowly in the cold but has an optimum growth temperature of 30°C is called a/an ______.

psychrotolerant microbe

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

flow cytometer

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

commensalism

A loopful of bacteria containing 1000 bacterial cells is inoculated into a nutrient broth and incubated. After a negligible lag phase, the culture goes into exponential growth for two hours. The generation time for the bacterium is fifteen minutes. Which equation is the correct one to determine the number of cells present after two hours of log phase growth?

1000 x 2^8

E. coli bacteria normally live in the human gut and produce vitamin K that the body uses. This is best termed a/an ______ relationship.

mutualistic

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

exponential phase

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

growth factor

An organism that can exist in both oxygen and oxygen-free environments is a/an ______.

facultative anaerobe

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

aerobe

Many lakes in the United States are suffering from periodic algae blooms, which can be thought of as an infection of the lake. Although the algae are naturally-occurring in the lake, when adjacent farm fields are over-fertilized with diammonium phosphate, the run-off deposits these nutrients in the lake, allowing the algae to grow without limit. Which of the following statements is incorrect regarding the overgrowth of algae?

the algae are heterotrophs

Microorganisms require large quantities of ______ for use in cell structure and metabolism.

macronutrients

Most of the dry weight of a microbial cell is from ______.

organic compounds

Which compound has the highest concentration in a cell?

H20

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

synergism

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

copper

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

photoautotroph

A halophile would grow best in

salt lakes

A microaerophile _______.

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

Which of the following represents a virus family name?

Herpesviridae

Viral nucleic acid types include which of the following?

All the choices are correct

(double strand DNA, single stranded DNA, double stranded RNA, single stranded RNA)

Classification of viruses into families involves determining all the following characteristics except ________.

biochemical reactions

Viral capsids are made from subunits called ______.

capsomeres

The core of every virus particle always contains ______.

either DNA or RNA

The correct sequence of events in viral multiplication is ________.

absorption, penetration, uncoating, synthesis, assembly, and release

A negative RNA virus must first ________.

synthesize a positive RNA copy of its genome

Creutzfeldt-Jacob disease is _______.

a spongiform encephalopathy of humans

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

icosahedral

(20 sides)

Host cells of viruses include ______.

all the choices are correct

(humans and other animals, plants and fungi, bacteria, protozoa and algae)

Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called ______.

latent

Viral tissue specificities are called ______.

tropisms

A naked virus only has a/an ______.

nucleocapsid

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

Which of the following is not a characteristic of a transformed cell?

decreased growth rate

Viruses acquire envelopes around their nucleocapsids during ______.

release

Oncogenic viruses include all the following except ______.

measles virus

Which of the following is/are type(s) of cytopathic effects?

all of the choices are correct

(inclusions in the nucleus, multi-nucleated giant cells, inclusions in the cytoplasm, rounding of cells)

Viruses exhibit all the following except ______.

metabolism

Helical and icosahedral are terms used to describe the shape of a viral ______.

capsid

Uncoating of viral nucleic acid _______.

all choices are correct

(does not occur in bacteriophage multiplication, involves enzymatic destruction of the capsid, occurs during penetration in the multiplication cycle, occurs before replication)

Which of the following is not a viral order in the classification system?

vaccinia virus

Which of the following is not associated with every virus?

envelope

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

uncoating

What structures are used by bacteriophages to attach to host cell receptors?

tail fibers

Viruses attach to their hosts via ______.

host glycoproteins

All of the following pertain to virus envelopes except ________.

located between the capside and nucleic acid