Microbio exam 3

An enzyme that copies DNA to make a molecule of RNA is

RNA polymerase.

In the figure, if base 4 is adenine, what is base 11' (remember the complimentary configuration of bases in DNA)?

adenine

In the figure, if base 4 is adenine, what is base 4'?

thymine

Which of the following is NOT a product of transcription?

a new strand of DNA

DNA is constructed of

two strands of nucleotide running in antiparallel configuration

A gene is defined as

a sequence of nucleotides in DNA that codes for a functional product.

When ultraviolet light strikes DNA, it can cause a specific type of damage. How is this damage best described?

Thymine bases on one strand of DNA, next to each other, are covalently linked together to form a thymine dimer.

The initial/first effect of ionizing radiation on a cell is that it causes

the formation of highly reactive ions.

Genetic change in bacteria can be brought about by

All of the answers are correct.

Transformation is the transfer of DNA from a donor to a recipient cell

as naked DNA in solution.

Biotechnology involves the

use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistant crop plants.

Which of the following is an advantage of using E. coli to make a human gene product?

Its genes are well known.

Restriction enzymes function as

bacterial enzymes that destroy phage DNA.

An agent used to reduce the number of bacteria on a toilet would most accurately be called a(n)

disinfectant

Which of the following pairs of terms is mismatched?

bacteriostatic – kills vegetative bacterial cells

Which of the following regarding antimicrobial control agents is FALSE?

Most chemical agents can achieve sterility.

The most resistant of the bacterial endospores can withstand boiling for up to

20 hours

If you were preparing nutrient agar at home and did not have an autoclave, what could you use to sterilize the nutrient agar?

pressure cooker at 121°C for 15 minutes

The preservation of beef jerky from microbial growth relies on which method of microbial control?

desiccation

All of the following are methods of food preservation EXCEPT

microwaves

Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper?

gamma radiation

Which of the following treatments is the most effective for controlling microbial growth?

140°C for 4 seconds

Which of the following methods is used to preserve food by slowing the metabolic processes of foodborne microbes?

freezing

Which of the following is a limitation of the autoclave?

It cannot be used with heat-labile materials.

Which of the following does NOT achieve sterilization?

pasteurization

Which of the following is the best method to sterilize heat-labile solutions?

membrane filtration

Ethylene oxide

is a sterilizing agent

Which of the following results in lethal damage to nucleic acids?

heat, radiation, and some chemicals

Which concentration of ethanol is the most effective bactericide?

70 percent

Which of the following is mismatched?

Florey and Chain – identification of Penicillium as the producer of penicillin

More than half of our antibiotics are

produced by bacteria

Most of the available antimicrobial agents are effective against

bacteria

In the presence of penicillin, a cell dies because

it undergoes lysis

Which of the following does NOT affect eukaryotic cells?

semisynthetic penicillins

Which of the following organisms would MOST likely be sensitive to natural penicillin?

Streptococcus pyogenes

A drug that inhibits mitosis, such as griseofulvin, would be more effective against

fungi

Drug resistance occurs

when antibiotics are used indiscriminately

Which of the following statements about drug resistance is FALSE?

It is found only in gram-negative bacteria.

One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in

increased susceptibility to disease

The major significance of Robert Koch's work is that

microorganisms cause disease

Genetic and metabolism are tied together by the fact that

the genes code for enzymes that catalyze reactions that result in characteristics

A person has brown eyes because?

Enzymes catalyze reactions that produce products that are brown

The enzyme that is responsible for synthesizing RNA is

Transcriptase

DNA directly participates in which of the following?

Replication and transcription

Genetics and metabolism are tied together by the fact that

The genes code for enzymes that catalyze reactions that result in characteristics

All of the following bases are found in RNA except

Thymine

A silent mutation is

Always a change in base sequence and sometimes a change in amino acid sequence.

The codon, UGA, would function as a stop codon on

mRNA.

Which would be a product of translation?

A protein (polypeptide)

Which require(s) living donor and recipient cells?

Conjugation only

Erectile dysfunction can be caused by

Cigarette smoke

The following use(s) sex pheromones.

Gram positive conjugation

Which of the following is due to a mistake in packaging of DNA?

Transduction

Chemicals in cigarette smoke that selectively cause cells with a mutation to replicate more than cells without a mutation are called

Promoters

Restriction enzymes are important because they

Generate overlapping sticky ends on DNA

A method of one-way gene transfer that requires cell-to-cell contact is

Conjugation

Which are not Methods of Sterilization?

Pasteurization and lyophilization

Endospores have resistance to some levels of ionizing radiation because they are

Desiccated

If you were asked to sterilize a heat-sensitive item (and not cause damage to the item), which of the following would be most suitable?

Ethylene oxide (carboxide)

Membrane filtration

Does not necessarily remove viruses

Major targets for disinfectant action include

Cell proteins and cell membranes

The most practical and efficient method of physical control is

Heat

Which term refers to a chemical that is used at safe levels in accordance with public health requirements?

Sanitizer

The chemical that is the active ingredient in Lysol is

Cresol

The difference between an antiseptic and a disinfectant is

Antiseptics are typically used on the skin

Criteria for usefulness of an antimicrobial agent does NOT include

Destruction of normal flora

A chemical that is not used much anymore because it is carcinogenic is

Formaldehyde

The most famous antibiotic, the first one discovered, one that inhibits bacterial cell wall synthesis, is

Penicillin

An example of a chemically-synthesized chemotherapeutic agent is

Sulfonamide

An antibiotic (by definition)

Is a chemical agent that is the product of some organism’s metabolism

For a non-growing (stationary-phase) bacterial culture, which should be most effective as an antimicrobial agent?

Polymyxin B

What is the drug of choice to treat anthrax?

Cipro

Measures to minimize drug resistance include

Discriminate use, Drug dose high and combination of drugs

Conceivably, the most common mechanism of microbial resistance is

Alteration of target molecule

Many cases of the flu on a college campus would be referred to as a(n)

Epidemic

Which of the following is a factor in the development of disease?

Number of pathogens, Vectors, and the ability to flourish outside of the body

Cholera, a very serious disease in many areas of the world, is normally transmitted via the

Gastrointestinal tract

An example of a disease normally transmitted via the blood is

Hepatitis

A disease organism that is present in high numbers in a specific geographical location is referred to as a(an

Endemic

Which organism requires fimbriae to stick to the lining of the genitourinary tract?

E.coli

What has been shown to remain active and infectious for hours on a toilet seat?

Herpes Virus

Which of the following diseases requires a tick vector for transmission?

Rocky Mountain Spotted Fever

A gene in a living organism is best defined as

A sequence of nucleotides in DNA that codes for a functional product.

Thymine dimers can be caused by

Ultraviolet radiation

The Genetic Code is made up of bases in

mRNA

Smoking cigarettes has been shown to be responsible for all of the following EXCEPT

Smoking cigarettes has been shown to be responsible for all of the above

A key discovery that contributed to the development of genetic engineering was

Restriction enzymes

Genetic engineering very often uses what to move hybrid plasmids into cells?

Transformation

Which statement is correct?

Cigarette smoke and ultraviolet radiation are chemical mutagenic agents

Genetic modification procedures can be used to

Clone genes for pest resistance, produce human growth hormone, and Clone genes for toxic waste clean up

An autoclave utilizes

Moist heat under pressure

Membrane filtration

Is a method of sterilization

What is Lyophilization

Is a method of preservation

A common method for sterilizing laboratory glassware is

Dry heat (oven)

Adding salt to ham or sugar to canned fruit is an example of what type of control?

Osmotic pressure

The major effect of using ionizing radiation on living organism is

The production of hydroxyl radicals from the water

Which is not a method of sterilization?

Ultraviolet radiation

Factors that normally affect disinfection include

Time, temperature, concentration, surrounding medium

One of the best disinfectants to use for a biological spill is

Bleach

Which of the following is FALSE?

Isopropyl alcohol is used to sterilize the skin