Mastering Microbiology Ch. 9 & 10

___________ is a technique used to quickly amplify specific sequences of DNA

Polymerase chain reaction

What is the temperature used for the extension step? a. 72 °C b. 60 °C c. 94 °C

a. 72 °C

DNA probes ________

are DNA fragments

PCR can be used to identify an unknown bacterium because a. all cells have RNA. b. DNA can be electrophoresed. c. DNA polymerase will replicate DNA. d. the RNA primer is specific. e. all cells have DNA.

d. the RNA primer is specific.

In nature, the function of restriction enzymes is to __________

destroy bacteriophage DNA

The evolutionary history of a group of organisms is called _________

phylogeny

A novel restriction enzyme makes staggered cuts in the two strands of DNA. The staggered cuts are called ________--

sticky ends

You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in the group a. Fungi. b. Animalia. c. Plantae. d. Bacteria. e. Archaea.

e. Archaea.

Into which group would you place a unicellular organism that has 70S ribosomes and a peptidoglycan cell wall? a. Plantae b. Animalia c. Fungi d. Protist e. Bacteria

e. Bacteria

Why is visualization not sufficient to properly identify bacteria? a. Not all bacteria can be seen with a light microscope. b. Identification is only needed in clinical specimens. c. Many unrelated bacteria can share the same shape. d. Bacteria have a limited set of shapes. e. Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.

e. Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.

Use the dichotomous key in the table to identify a gram-negative coccus. a. Staphylococcus b. Pseudomonas c. Micrococcus d. Streptococcus e. Neisseria

e. Neisseria

What best describes the difference between classification and identification?

Identification is more practical in its purpose. For example, it is used to diagnose infection

What is the function of the primers in PCR? a. They are the monomer building blocks from which the DNA strand is synthesized. b. They provide a 3' end for the DNA polymerase. c. They provide energy for the DNA polymerization reactions. d. They polymerize free nucleotides to form the new DNA strands.

b. They provide a 3' end for the DNA polymerase.

How many questions are needed in this dichotomous key to determine if the unknown is Bacteroides? a. Four b. Five c. Two d. Three

d. Three

A good cloning vector _________

should have a gene or genes that allow for selection of transformed host cells

In genetic engineering, antibiotic-resistance genes are usually cloned into vectors to ____________

allow selection for bacteria containing the vector

The process of making multiple copies of a DNA molecule is referred to as __________

amplification

What is the sequence of the temperatures of a typical PCR reaction? a. 94 °C, 60 °C, 72 °C b. 72 °C, 60 °C, 94 °C c. 72 °C, 94 °C, 60 °C d. 60 °C, 72 °C, 94 °C e. 94 °C, 72 °C, 60 °C

a. 94 °C, 60 °C, 72 °C

Which of the following statements about recombinant DNA technology is FALSE? a. It has limited application because genes of interest cannot be moved from one type of cell to another. b. It allows researchers to make protein products of a gene. c. It allows researchers to make many copies of a gene of interest. d. It can be used to screen individuals for many different types of genetic diseases.

a. It has limited application because genes of interest cannot be moved from one type of cell to another.

Which of the following is an advantage of using E. coli to make a human gene product? a. Its genes are well known. b. Endotoxin may be in the product. c. Endotoxin may be in the product and it does not secrete most proteins. d. It does not secrete most proteins. e. It cannot process introns.

a. Its genes are well known.

A source of heat-stable DNA polymerase is a. Thermus aquaticus. b. Bacillus thuringiensis. c. Agrobacterium tumefaciens. d. Saccharomyces cerevisiae. e. Pseudomonas.

a. Thermus aquaticus.

Why are flowcharts useful for dichotomous keys? a. They allow the researcher to visualize relationships between different bacteria. b. They allow the researcher to get the answer without having to do many tests. c. They provide a map to the answer.

a. They allow the researcher to visualize relationships between different bacteria.

Which statement best describes restriction enzymes? a. They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences. b. They randomly cut DNA molecules to generate numerous fragments. c. They are necessary for the polymerase chain reaction (PCR) to occur. d. They can cut only circular plasmid DNA.

a. They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences.

What is the hallmark of dichotomous keys? a. They consist of a series of paired statements, in which only one statement of each pair applies to a given organism. b. They only relate to the shape of the cell. c. They are open-ended questions. d. They only relate to biochemical processes of the cell.

a. They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.

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.

Bioinformatics is the use of computer technology to compare and analyze genome sequence. a. True b. False

a. True

In recombinant DNA technology, a vector is a self-replicating segment of DNA, such as a plasmid or viral genome. a. True b. False

a. True

Serological testing is used for screening bacterial isolates for similarities. a. True b. False

a. True

The Bt toxin derived from Bacillus thuringiensis has been introduced into some crop plants to make them resistant to insect destruction. a. True b. False

a. True

How many answers are there to a question in a dichotomous key flowchart? a. Two b. Four c. Three d. Any number of answers are possible.

a. Two

Biochemical tests _________________. a. are the main methods used to identify unknown bacteria b. are used to determine rate of growth c. are the most effective way to determine bacterial shape d. are visualized using microscopes

a. are the main methods used to identify unknown bacteria

PCR stands for a. polymerase chain reaction. b. polymerization copying rapidly. c. polymerase copy reaction.

a. polymerase chain reaction.

How many pieces will EcoRI produce from the plasmid shown in the figure? a. 1 b. 2 c. 3 d. 4 e. 5

b. 2

At this point in time, scientists believe the vast majority of the domain Bacteria have been discovered. a. True b. False

b. False

The Ti plasmid isolated from Agrobacterium can be used to insert DNA into any type of plant. a. True b. False

b. False

The highest level in the current taxonomic hierarchy is "Kingdom." a. True b. False

b. False

The practice of breeding plants and animals for desirable traits, such as high crop yield, is called natural selection. a. True b. False

b. False

Why is DNA polymerase from Thermus aquaticus ideal for PCR? a. It does not require primers. b. It can withstand the high temperatures associated with PCR. c. It does not require energy to polymerize DNA. d. It can synthesize DNA 5' to 3' and 3' to 5'.

b. It can withstand the high temperatures associated with PCR.

How would the results be different if this organism was Salmonella? a. It would be a rod. b. It would produce hydrogen sulfide. c. It would not ferment lactose. d. It would not tolerate oxygen.

b. It would produce hydrogen sulfide.

While working with a broth culture of archaea in the laboratory, you accidentally spill some of the microorganisms on yourself. Do you need to be concerned about developing an infection? Why or why not? a. No; archaea are prokaryotic, so they cannot cause infection. b. No; archaea are not pathogenic. c. Yes; certain archaea can be pathogenic, so an infection could occur. d. Yes; all infectious prokaryotes are archaea.

b. No; archaea are not pathogenic.

Which of the following is an application that uses PCR? a. Sequencing a gene b. Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism c. Providing enough DNA for cloning into another organism d. Diagnosing a disease

b. Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism

How do the strands separate during PCR? a. The DNA polymerase breaks the hydrogen bonds between the two strands. b. The high heat of the denaturation step breaks the hydrogen bonds between the two strands. c. The primers separate the strands during the annealing step. d. The cycling of the temperatures breaks the hydrogen bonds between the two strands.

b. The high heat of the denaturation step breaks the hydrogen bonds between the two strands.

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

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

What is the end goal of PCR? a. To increase the pool of different DNA sequences b. To quickly increase the number of copies of a specific DNA sequence c. To allow cells to make DNA faster, thereby growing faster

b. To quickly increase the number of copies of a specific DNA sequence

Following an endospore stain, how does one distinguish endospores from vegetative cells? a. Vegetative cells are purple, endospores are pink. b. Vegetative cells are pink, endospores are green. c. Vegetative cells are pink, endospores are purple. d. Vegetative cells are green, endospores are pink.

b. Vegetative cells are pink, endospores are green.

Which of the following methods could be used to differentiate between a member of domain Bacteria and a member of domain Archaea? a. You could see if the organism produces rRNA. b. You could look for the presence of peptidoglycan. c. You could see if the organism can survive in an extreme environment. d. You could look for the presence of mitochondria. e. All of the above would work. f. None of the above would work.

b. You could look for the presence of peptidoglycan.

Foreign DNA can be inserted into cells using a variety of different methods. Which method involves the formation of microscopic pores in the cell's membrane? a. heat shock b. electroporation c. protoplast fusion d. transformation

b. electroporation

In which direction does DNA polymerase synthesize the new DNA strand? a. Both 5' to 3' and 3' to 5' b. 3' to 5' c. 5' to 3'

c. 5' to 3'

Which of the following methods could be used to identify the source of an outbreak? a. production of a recombinant protein b. reverse genetics c. DNA fingerprinting d. artificial selection

c. DNA fingerprinting

Which enzyme would cut this strand of DNA? GCATGGATCCCAATGC a. Enzyme Recognition HaeIII GGCC CCGG b. Enzyme Recognition Pst ICTGCG GACGTC c. Enzyme Recognition BamHI GGATCC CCCTAGG d. Enzyme Recognition EcoRI GAATTC CTTAAG e. Enzyme Recognition HindIII AAGCTT TTCGAA

c. Enzyme Recognition BamHI GGATCC CCCTAGG

Which of the following is an example of a dye used in a simple stain? a. Eosin b. Nigrosin c. Methylene blue d. Carbolfuchsin

c. Methylene blue

What test result indicates that the unknown can utilize citrate as its sole carbon source? a. The culture becomes turbid. b. It turns the medium black. c. The medium turns blue. d. The medium turns pink.

c. The medium turns blue.

How are negative stains different from other types of stains? a. They stain the desired structure or specimen black. b. They stain more than one type of specimen. c. They stain the background, leaving the cells colorless.

c. They stain the background, leaving the cells colorless.

What is the fundamental purpose of staining in light microscopy? a. To make the specimen appear larger in the microscope b. To kill the specimen c. To increase the contrast and visibility of the specimen d. To see the specimen without the aid of a microscope

c. To increase the contrast and visibility of the specimen

A restriction fragment is a. a gene. b. a segment of mRNA. c. a segment of DNA. d. cDNA. e. a segment of tRNA.

c. a segment of DNA.

A clone is a. a mound of cells on an agar medium. b. a taxon composed of species. c. genetically identical cells derived from a single cell. d. a genetically engineered cell. e. None of the answers is correct.

c. genetically identical cells derived from a single cell.

Which of the following is NOT a desired characteristic of DNA vectors used in gene cloning procedures? a. may replicate in several species b. circular form of DNA or integrates into the host chromosome c. large size d. self-replication e. has a selectable marker

c. large size

The reaction catalyzed by reverse transcriptase is a. mRNA → protein. b. tRNA → mRNA. c. mRNA → cDNA. d. DNA → mRNA. e. DNA → DNA.

c. mRNA → cDNA.

The sequencing of rRNA__________

can yield information about evolutionary relatedness

To express a human gene in a bacterium. cDNA must be made because bacteria__________

cannot remove introns

Why are archaea and bacteria—both collections of prokaryotic organisms—grouped into different domains while organisms like fungi and animals are in the same domain? a. Bacteria and archaea differ significantly in their intracellular organization and structure, but fungi and animals have similar intracellular structure. b. The DNA sequences of bacteria and archaea are more different than animals and fungi. c. Fungi and animals look much more similar than bacteria and archaea. d. Bacteria and archaea differ significantly in their rRNA sequences, but fungi and animals share some rRNA characteristics.

d. Bacteria and archaea differ significantly in their rRNA sequences, but fungi and animals share some rRNA characteristics.

Which of the following attaches the target gene to a desired location? a. Plasmids b. Chromosomal DNA c. Restriction enzymes d. DNA ligase

d. DNA ligase

What provides the energy for DNA polymerization in a PCR reaction? a. Template DNA b. Primers c. DNA polymerase d. Deoxyribonucleoside triphosphates

d. Deoxyribonucleoside triphosphates

The first question in this dichotomous key addresses a. bacterial morphology. b. metabolic characteristics. c. oxygen tolerance. d. Gram stain differences.

d. Gram stain differences.

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

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

Why is the unknown in this example not Pseudomonas? a. It is a rod-shaped cell. b. It is a Gram-negative cell. c. It can tolerate oxygen. d. It ferments lactose.

d. It ferments lactose.

How does the malachite green stain enter an endospore? a. It is mixed with hydrochloric acid. b. It is dissolved in alcohol. c. It is mixed with the mordant tannic acid. d. It is heated.

d. It is heated.

How is fermentation of lactose detected? a. The acetoin produced turns the medium pink. b. The medium become turbid when exposed to air. c. The cells form a black precipitant. d. The drop in pH turns the indicator dye yellow.

d. The drop in pH turns the indicator dye yellow.

What is a thermocycler? a. The process of cycling through the different temperatures of a PCR reaction 30 times b. The special DNA polymerase, used in a PCR reaction, that can tolerate the high temperatures c. The name for the DNA primers used in a PCR reaction d. The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR

d. The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR

Serological testing is based on the fact that a. all bacteria have the same antigens. b. bacteria clump together when mixed with any antibodies. c. antibodies cause the formation of antigens. d. antibodies react specifically with an antigen. e. the human body makes antibodies against bacteria.

d. antibodies react specifically with an antigen.

The Human Genome Project, which was completed in 2003, was focused on a. identifying all of the genes in the human genome. b. finding a cure for all human genetic disorders. c. determining all of the proteins encoded by the human genome. d. determining the nucleotide sequence of the entire human genome. e. cloning all of the genes of the human genome.

d. determining the nucleotide sequence of the entire human genome.

If two organisms have similar rRNA sequences, you can conclude that they a. live in the same place. b. will have different G-C ratios. c. will both ferment lactose. d. evolved from a common ancestor. e. mated with each other.

d. evolved from a common ancestor.

The phylogenetic classification of bacteria is based on a. habitat. b. cell morphology. c. diseases. d. rRNA sequences. e. Gram reaction.

d. rRNA sequences.

Self-replicating DNA used to transmit a gene from one organism to another is a a. clone. b. Southern blot. c. PCR. d. vector. e. library.

d. vector.

Which is NOT a characteristic of prokaryotes?

use mitosis