Question 1

Heavy metals are effective antimicrobial agents but are not widely used because of their high toxicity to humans.

Accepted Answer

Heavy metals such as silver, copper, and zinc are effective antimicrobial agents, but their use is limited due to their high toxicity to humans.

Question 2

The disinfectant action of phenol and phenolic derivatives mainly is due to

Accepted Answer

Phenol and phenolic derivatives primarily act by damaging the cellular membrane and denaturing proteins present within the microorganisms, thereby disrupting their metabolic processes and leading to cell death.

Question 3

Iodine can be complexed with an organic carrier to form water-soluble, stable complexes called __________, which release iodine slowly and eliminate skin burns and irritation associated with iodine use.

Accepted Answer

Iodophors are complexes of iodine with an organic carrier that release iodine slowly and eliminate skin burns and irritation associated with iodine use. Iodides are simply compounds containing iodine, tinctures typically refer to alcoholic solutions of medicinal substances, and iodochromes are compounds used for staining biological tissues.

Question 4

Antiseptics are generally regulated by the

Accepted Answer

The Food and Drug Administration (FDA) regulates antiseptics as they are considered drugs that are used to kill or prevent the growth of microorganisms on living tissue. The FDA ensures that antiseptics are safe and effective for their intended use.

Question 5

Which of the following is (are) a sterilizing gas(es) that can be used on heat-sensitive materials?

Accepted Answer

Ethylene oxide is a sterilizing gas that can be used on heat-sensitive materials. Glutaraldehyde is a liquid sterilant, not a gas. Chlorine gas is toxic and not typically used for sterilization. Isopropanol is an antiseptic, not a sterilizing agent.

Question 6

The disinfectant of choice for municipal water supplies is __________.

Accepted Answer

Chlorine is the disinfectant of choice for municipal water supplies due to its effectiveness in killing a wide range of harmful microorganisms and its ability to remain active in the water distribution system. Fluorine is not commonly used as a disinfectant for water supplies, as it is primarily added for dental health benefits. Ultraviolet light can be used for disinfection, but it is not as reliable as chlorine in killing all types of microorganisms.

Question 7

The higher the phenol coefficient value, the _______ effective the disinfectant under the test conditions.

Accepted Answer

The answer of The higher the phenol coefficient value, the...

Question 8

Although heavy metals are no longer widely used as germicides, __________ is an effective algicide in lakes and swimming pools.

Accepted Answer

Copper sulfate is commonly used as an effective algicide in lakes and swimming pools, as it can kill algae and other unwanted bacteria without harming humans or animals. Lead acetate, silver nitrate, and mercuric chloride are not commonly used today due to their toxicity and potential environmental hazards.

Question 9

Alcohols are widely used as antiseptics and disinfectants because they are effective against endospores as well as vegetative cells.

Accepted Answer

Alcohols are effective against vegetative cells of bacteria and fungi, and some viruses, but they are not effective against bacterial endospores, which are highly resistant to most disinfectants.

Question 10

Betapropiolactone is not as useful as ethylene oxide as a sterilizing agent because it does not penetrate materials as readily as ethylene oxide.

Accepted Answer

Betapropiolactone is a liquid sterilizing agent that is commonly used in experiments and animal research. However, it is not as effective as ethylene oxide as a sterilizing agent because it does not penetrate materials as easily as ethylene oxide. Ethylene oxide is a gas that can permeate even the most porous materials, making it a more reliable sterilizing agent for medical devices and equipment.

Question 11

The disinfecting properties of Lysol, a common household disinfectant, depend upon the presence of __________.

Accepted Answer

The answer of The disinfecting properties of Lysol, a common...

Question 12

The disinfectant screening method that is known as the ________ _________ test, which is used to measure the potency of a disinfectant.

Accepted Answer

The answer of The disinfectant screening method that is known...

Question 13

The two most important alcohol germicides are __________ and __________.

Accepted Answer

Ethanol and isopropanol are the two most important alcohol germicides. They are effective against a wide range of microorganisms and have a broad spectrum of activity. Methanol and butanol are less commonly used as germicides due to their toxicity and flammability.

Question 14

Amphipathic organic molecules that serve as disinfectants by disrupting membranes and denaturing proteins are called

Accepted Answer

Detergents are amphipathic organic molecules that disrupt membranes and denature proteins, which makes them effective disinfectants. Sterilants are agents that kill or remove all forms of microbial life, including bacterial endospores. Oxidants work by generating reactive oxygen species that damage microbial cells. Soaps are not typically considered disinfectants as they do not have significant antimicrobial properties.

Question 15

Disinfectants are generally regulated by the

Accepted Answer

Disinfectants are regulated by the Environmental Protection Agency (EPA) in the United States. The EPA is responsible for setting standards and guidelines for the use and effectiveness of disinfectants, as well as approving new disinfectant products for use in various settings. The FDA regulates products related to food, drugs, and medical devices. The National Institutes of Health mainly conducts research related to health and disease. The Centers for Disease Control and Prevention (CDC) focuses on preventing and controlling infectious diseases, but they do not regulate disinfectants.

Question 16

Bacteriophage therapy was developed after antibiotics were first discovered and used for treating bacterial infections.

Accepted Answer

Bacteriophage therapy, which uses viruses to target and kill bacteria, was discovered and initially developed before the widespread use of antibiotics, with significant research and application occurring in the early 20th century.

Quiz 8: Control of Microorganisms in the Environment