micro exam 3 HW

A Salmonella virulence operon has three genes that are important for invasion of host cells. These proteins are not produced when the bacteria are growing outside of the host, and are only produced when the bacteria are growing inside the host. Based on this information, how many promoters are there, and what is the mode of regulation? 3; repressible 1; repressible 3; inducible 1; inducible

1; inducible

Which of the following best explains why the pressure cooker is so important in the canning process?

A pressure cooker utilizes steam to create a higher-pressure environment that allows the food to cook at higher temperatures than normal. The higher temperatures kill most contaminating microbes and endospores and therefore effectively sterilize the food.

A strain of E. coli has been isolated from a patient with serious diarrhea. In addition to its chromosome, it has a plasmid. Strains that lose the plasmid become non-pathogenic, and non-pathogenic strains are able to cause diarrhea if transformed with the plasmid. What type of plasmid is this? A bacteriocin plasmid A virulence plasmid An (R) plasmid An (F) plasmid

A virulence plasmid

How do restriction enzymes cut DNA sequences? A. They cut DNA at sites, called recognition sites, that have specific nucleotide sequences. B. They cut DNA at sequences that have lots of adenine bases. C. They have the ability to cut DNA randomly.

A. They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.

In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene? A. To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene B. To replace a defective gene with a working gene C. To remove an undesirable gene D. To insert a desirable gene

A. To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene

Why would a recombinant DNA molecule be inserted into a host cell? A. Plasmids cannot be isolated outside of a host cell. B. It can be copied, transcribed, and translated into a desired protein. C. Restriction enzymes can only be used inside of a cell. D. It can protect the recombinant DNA.

B. It can be copied, transcribed, and translated into a desired protein.

Which of the following attaches the target gene to a desired location? A.Plasmids B. Chromosomal DNA C. DNA ligase D. Restriction enzymes

DNA ligase

If you wanted to evaluate a new disinfectant for effectiveness under the conditions of its intended use, the best evaluation technique would be the __________ test. in-use use-dilution phenol coefficient Kelsey-Sykes capacity

In-use

An R (resistance) plasmid can be transferred from E. coli to Salmonella in culture. Which of the following would suggest that transformation is the transfer mechanism? Plasmid is not found in the recipient when DNase is added to the culture medium. Plasmid is found in recipient cells only when phages are present. Plasmid is only found in the recipient only when F (fertility) plasmid sequences are present. Plasmid is only found in recipient when there is direct between donor and recipient.

Plasmid is not found in the recipient when DNase is added to the culture medium.

Which of the following statements regarding vectors is FALSE? Vectors are generally over 100,000 base pairs in size. Vectors are usually autonomously replicating DNA molecules. Cloning vectors frequently contain sequences necessary for expression of inserted sequences. Cloning vectors include a "marker" to facilitate identification of cells containing them. A useful vector contains multiple restriction sites for insertion of DNA.

Vectors are generally over 100,000 base pairs in size.

Which of the following is an example of microbial control? A.Sue washes off the vegetables before serving them in a meal. B. Mary warms food up in a microwave before putting it on the table. C. Sue uses bleach to clean the kitchen counters. D. Mary places leftovers in the refrigerator after the meal.

a, c, d

Formalin (37% formaldehyde) is used for antisepsis. sanitization. disinfection. sterilization. both disinfection and sterilization.

both

Since Strachan's hypothesis is almost impossible to demonstrate using experimentation, how did he most likely arrive at such an assertion? by comparing cases of allergy-associated disorders from years past to those of the present by comparing vaccination records of individuals with immune disorders and those without through the observation that older people rarely get sick by intentionally exposing children to various pathogens

by comparing cases of allergy-associated disorders from years past to those of the present

Put the following events in the construction of a recombinant DNA molecule in the correct order: a. ligation of desired gene to plasmid DNA b. introduction of the plasmid into bacteria c. restriction enzymes cut gene of interest and plasmid DNA d. growth of cells on an antibiotic-containing medium a, d, c, b b, c, a, d c, a, b, d d, a, b, c

c,a,b,d

hich of the following is NOT a goal of recombinant DNA technology? creating organisms capable of producing useful products combining genetic material from more than one organism to produce new useful organisms being able to remove or correct damaging traits in humans eliminating undesirable traits from livestock or crops making it possible to clone humans

making it possible to clone humans

Exposure to which of the following microscopic substances will most likely lead to an allergy in an individual with an over reactive immune system? pollen viruses disinfectants bacteria

pollen

Mutagens are useful in biotechnology research for producing new organisms which have beneficial traits from two or more organisms. removing undesirable traits from microbes. selecting genetic mutants resistant to radioactivity. producing organisms with altered phenotypes. producing DNA fragments for cloning.

producing organisms with altered phenotypes

Which of the following enzymes can make specific cuts in DNA molecules? DNA polymerase DNA ligase reverse transcriptase restriction enzymes

restriction enzymes

According to the readings in Chapter 9, which of the following is a chemical method to control the growth of microbes? radiation desiccation moist heat surfactants

surfactants

Handwashing with regular soap is effective because __________. the hydrophobic end of the soap molecule breaks up oily deposits and the hydrophilic end of the molecule attracts water. This combination makes soap a good de-germing agent the hydrophobic end of the soap molecule attaches to the cell wall of bacteria and the hydrophilic end of the molecule attracts water. The result is that the bacteria are washed away with the water the fatty acid tail of a soap molecule is an excellent oxidizing agent, while the opposite end of the molecule contains alcohol soap is an excellent antimicrobial agent

the hydrophobic end of the soap molecule breaks up oily deposits and the hydrophilic end of the molecule attracts water. This combination makes soap a good de-germing agent