Question 1

The reduction of the microbial population to levels that are considered safe by public health standards is called

Accepted Answer

Sanitization refers to the reduction of microbial population to levels that are considered safe for public health. Disinfection and sterilization refer to more complete elimination of all microbes, while antisepsis refers to killing microbes on living tissue.

Question 2

An agent that specifically kills fungi but not other kinds of microorganisms is also known as a

Accepted Answer

A fungicidal agent specifically kills fungi, whereas a fungistatic or mycostatic agent only inhibits the growth of fungi, and a germicidal agent may also kill other types of microorganisms such as bacteria and viruses.

Question 3

Which of the following inhibits bacterial growth but does not kill bacteria?

Accepted Answer

Bacteriostatic agents inhibit the growth and reproduction of bacteria, but do not kill them. This is in contrast to bactericidal agents, which kill bacteria. Lysozyme is an enzyme that breaks down the cell walls of bacteria, leading to their death. Antiseptic agents are substances that kill or prevent the growth of microorganisms on living tissue.

Question 4

Sterilization involves __________ all viable microorganisms.

Accepted Answer

Sterilization is a process that eliminates or kills all forms of life and other biological agents from a specified area, object, or medium. This includes the removal or destruction of all viable microorganisms, achieved through methods that either kill (e.g., heat, radiation, chemicals) or physically remove them (e.g., filtration).

Question 5

Which of the following influence(s)the efficiency of an antimicrobial agent?

Accepted Answer

All of the choices listed can influence the efficiency of an antimicrobial agent. The concentration of the agent can affect how effectively it kills or inhibits growth of microorganisms. The duration of exposure can also impact this, as a longer exposure time allows for more effective contact with microorganisms. Temperature can also play a role in antimicrobial efficacy, as some agents work better at higher or lower temperatures. Therefore, all of these factors should be considered when selecting and using an antimicrobial agent.

Question 6

Larger populations generally are killed as rapidly as smaller populations.

Accepted Answer

Larger populations may take longer to kill off due to their size, but they are not generally killed as rapidly as smaller populations.

Question 7

All germicides are capable of killing all pathogenic organisms and endospores.

Accepted Answer

Not all germicides are capable of killing all pathogenic organisms and endospores. The effectiveness of a germicide depends on various factors such as the type of microorganism, concentration of the germicide, and exposure time. Some germicides may only be effective against certain types of microorganisms, while others may require longer exposure time or higher concentrations to kill certain pathogens or endospores.

Question 8

The prevention of infection caused by microorganisms is called

Accepted Answer

Antisepsis specifically refers to the prevention of infection caused by microorganisms on living tissue, such as skin or mucous membranes. Disinfection and sterilization may also prevent infection, but they refer to the killing or removal of microorganisms on surfaces or objects, not necessarily on living tissue. Sanitization generally refers to reducing the number of microorganisms on a surface to a safe level, but may not necessarily prevent infection.

Question 9

The time required to kill 90% of the microorganisms or spores in a sample at a specified temperature is the

Accepted Answer

The decimal reduction time (D value) is the correct answer. It refers to the time required to kill 90% of the microorganisms or spores in a sample at a specified temperature. The thermal death time (TDT) refers to the time required to kill all microorganisms or spores in a sample at a specific temperature, and the thermal death point (TDP) is the temperature required to kill all microorganisms or spores in a sample in a specified time. The z value is the change in temperature required to change the D value by a factor of 10.

Question 10

When antiseptics and disinfectants are compared,antiseptics are generally

Accepted Answer

Antiseptics are designed to be used on living organisms, and therefore are generally less toxic than disinfectants, which are meant to be used on inanimate objects and surfaces. Disinfectants are often more concentrated and have a higher potential for toxicity.

Question 11

Which of the following represents the best definition for microbial death?

Accepted Answer

Microbial death refers to the permanent loss of the ability of a microorganism to reproduce or grow on a medium that normally supports its growth. Option A refers to a lack of growth on minimal medium, which does not necessarily indicate microbial death. Option C refers to a change in morphology, which is not necessarily indicative of microbial death either. Option D is incorrect as option B adequately describes microbial death.

Question 12

An agent that prevents the growth of bacteria without causing irreversible damage to the bacteria is referred to as __________.

Accepted Answer

The answer of An agent that prevents the growth of...

Question 13

An agent that kills bacteria is referred to as __________.

Accepted Answer

The answer of An agent that kills bacteria is referred...

Question 14

Microorganisms show differential sensitivity to antimicrobial agents.

Accepted Answer

Microorganisms have varying sensitivity to different antimicrobial agents. Some microorganisms may be more susceptible to certain antibiotics or disinfectants, while others may be more resistant. This variation in sensitivity can be influenced by factors such as the microorganism's genetic makeup or its ability to produce enzymes that break down the antimicrobial agent.

Question 15

The destruction or removal of all viable organisms is called

Accepted Answer

The term "sterilization" refers to the complete destruction or removal of all viable organisms, including bacterial endospores, from a surface, object or solution. This is a level of microbial control that surpasses disinfection and sanitization. Antisepsis refers specifically to the use of antimicrobial agents on living tissue to prevent or reduce the risk of infection.

Question 16

Which will require a longer time to kill?

Accepted Answer

A larger population of microorganisms will require a longer time to kill because there are more microorganisms to destroy. The larger the population, the more time it will take for the antimicrobial agent to reach and kill all the microorganisms.

Question 17

A(n)__________ is a chemical that can be used to sterilize materials.

Accepted Answer

A sterilant is a chemical that is capable of killing all forms of microorganisms, including bacterial spores. Unlike disinfectants and antiseptics, which only reduce the number of microorganisms, sterilants completely eliminate them.

Question 18

Which of the following environmental factors generally do(es)not have an impact on the efficiency of an antimicrobial agent?

Accepted Answer

Refractive index is not an environmental factor that affects the efficiency of an antimicrobial agent. pH, presence of a biofilm, and concentration of organic matter can all affect the ability of antimicrobial agents to effectively kill or inhibit microbial growth.

Question 19

The substantial reduction of the total population of microorganisms on inanimate objects and the destruction of potential pathogens is called

Accepted Answer

Disinfection refers to the process of eliminating or reducing harmful microorganisms from inanimate objects and surfaces, particularly pathogens.

Question 20

The rate of killing by an antimicrobial agent may slow when the microbial population has been greatly reduced because the remaining population may have a high proportion of resistant organisms.

Accepted Answer

This phenomenon is known as "selective pressure" and can result in the survival and proliferation of resistant organisms that were previously rare in the population. This can lead to the development of antimicrobial resistance over time.

Quiz 8: Control of Microorganisms in the Environment