Knapp Exam 2 Practice Questions

Which of the following was developed from Grffith's 1928 experiment? a. some pathogenic bacteria cannot be heat-killed, bacterial virulence is related to temperature resistance b. Streptococcus pneumoniae causes disease c. DNA from dead encapsulated bacteria can transform living bacteria into encapsulated bacteria d. dead encapsulated bacteria can cause disease

c. DNA from dead encapsulated bacteria can transform living bacteria into encapsulated bacteria

Which of the following steps is generally NOT part of the life cycle of a lytic phage? a. the progeny phage formed inside the cell lyses the host cell b. only the viral genome typically enters the host bacterial cell c. a prophage forms in the host bacterial cell d. the phage DNA is transcribed, and resulting mRNA is translated to make capsid proteins e. all of the above are part of the lytic phage cycle

c. a prophage forms in the host bacterial cell

Lysogeny occurs in certain bacteria; the equivalent process in an animal cell is best represented by a a. a prion b. a viral infection that quickly kills the host c. a retrovirus infection d. a cold virus (rhinovirus) infection of respiratory epithelial cells e. none of the above

c. a retrovirus infection

MacConkey's Agar is a growth medium used for the isolation of gram-negative enteric bacteria. Crystal violet and bile salts inhibit growth of gram-positive bacteria; neutral red is a pH indicator, and lactose is present to detect the presence of lactose fermenting bacteria. Other ingredients include peptone and proteose peptone. Based on this information, determine which terms apply to this growth medium. a. it is a selective medium b. it is a differential medium c. it is a defined medium d. it is a complex medium e. a and c f. a, b, and c g. a and b h. a, b, and d

d. a, b, and d (selective, differential, complex)

Which of the following among A-D is false regarding all types of viruses? a. they all have a genome of either RNA or DNA b. they all have a coat of capsid proteins surrounding their nucleic acid c. they all require a host in order to form new viral particles d. all viruses possess an envelope e. none of A-D is false

d. all viruses possess an envelope

Which of the following could not be used as a criterion to identify viruses? a. biochemical tests for metabolic pathways b. presence or absence of glycoprotein spikes c. nucleic acid types d. the shape and size of the capsid e. number and types of capsomeres

a. biochemical tests

Cell-mediated transfer of a plasmid to another cell is a. conjugation b. transcription c. transduction d. transfromation e. translation

a. conjugation

Viroids lack a. proteins b. infectivity c. nucleic acid d. catalytic activity e. none of the above

a. proteins

Which statement among A-C is false concerning retroviruses: a. the information flow of such viruses is: DNA to RNA to protein b. they can form a proviurs c. they can remain in the provirus state while simultaneously initiating production of new viral particles d. none of A-D is false

a. the information flow of such viruses is: DNA to RNA to protein (retroviruses go from RNA to DNA)

Which statement among A-D is false regarding aerotolerant anaerobic bacteria? a. they are capable of using oxygen as part of their metabolism b. they possess protective enzymes that prevent damage from reactive oxygen species c. they can grow among, or with, aerobic and anaerobic types of bacteria d. none are false

a. they are capable of using oxygen as part of their metabolism

In comparing a bacterial virus infection to an animal virus infection, which of the following among A-D would not occur in a bacteriophage infection process? a. uncoating b. attachment to host cell c. transcription of viral genome d. assembly of capsids e. all of the above would occur during bacteriophage infection

a. uncoating

Which statement among A-D is false regarding animal virus infections? a. uncoating refers to the process of viral exit from the host cell b. depending on the virus type, assembly of viruses may occur in the nucleus or cytoplasm c. budding is a mechanism of virus exit that can lead to acquisition of the viral envelope d. endosome formation is a mechanism that eventually allows for the genome to be freed from the capsid e. none of A-D is false

a. uncoating refers to the process of viral exit from the host cell

The host range of a virus is determined by a. whether the glycoproteins or capsid proteins on its surface recognize those of the host cells b. whether its nucleic acid is DNA or RNA c. the proteins in the host's cytoplasm d. the enzymes produced by the virus before it infects the cell e. the enzymes carried by the virus

a. whether the glycoproteins or capsid proteins on its surface recognize those of the host cell

For many bacterial types, this component is an absolute requirement for growth, for others it may be toxic, and still others can live with or without it. This component is: a. carbon b. O2 c. sulfur d. phosphorus e. nitrogen

b. O2

Which of the following statements is true? a. in terms of killing effect and penetration, non-ionizing radiation is generally more effective than ionizing radiation b. an antimicrobial agent exhibiting bactericidal activity would always show a decrease in viable count c. implementing cold temperatures for food preservation has a bacteriocidal effect rather than bacteriostatic effect d. disinfection is always a process that yields sterilization e. none of the above are true

b. an antimicrobial agent exhibiting bactericidal activity would always show a decrease in viable count

Plasmids differ from transposons in that plasmids a. become inserted into chromosomes b. are self-replicated outside the chromosome c. move from chromosome to chromosome d. carry genes for antibiotic resistance e. none of the above

b. are self-replicated outside the chromosome

A segment of DNA that moves from one part of a chromosome to a different location in the same chromosome a. is a process that occurs via transformation b. is how a transposon functions c. is the process of specialized transduction d. leads to the formation of an F+ cell

b. is how a transposon functions

Which statement is true concerning RNA viruses? a. they all must convert their RNA genome into DNA b. the genome of a single-stranded (+) RNA virus can serve directly as mRNA c. a single-stranded (-) RNA virus cannot produce viral proteins d. all are true

b. the genome of a single-stranded (+) RNA virus can serve directly as mRNA

What would the three bacterial types described below all have in common? 1: a psychrophilic, alkalophilic, facultative anaerobe 2: a mesophilic, halophilic, aerotolerant anaerobe 3: a hyperthermophilic, acidophilic, obligate anaerobe a. they would all grow in high salt concentrations b. they would all be capable of growing in the absence of oxygen c. the ability to grow well under low pH conditions d. they would all be capable of growing in the presence of oxygen e. they would all be capable of growing at temperatures above 50 C

b. they would all be capable of growing in the absence of oxygen

Which of the following is false regarding all types of viruses? a. they all have either RNA or DNA b. they all have a coat of capsid proteins surrounding their nucleic acid c. they all possess RNA Depended RNA Polymerase d. they all require a host to replicate e. none of A-D are false

c. they all possess RDRP

Transfer of DNA from a donor to a recipient cell by a bacteriophages is a. conjugation b. transcription c. transduction d. transfromation e. translation

c. transduction

You add 10 g/L of a nutrient to a growing liquid culture of E. coli; after five hours, you observe that in response to the addition of the nutrient, the quantity of cell mass has doubled. The nutrient source of which element is the one you added that most likely yielded this effect? a. phosphorus b. sulfur c. hydrogen d. carbon e. nitrogen

d. carbon

What are prions? a. mobile segments of DNA b. tiny molecules of RNA that infect plants c. viral DNA that has had to attach itself to the host genome d. misfolded versions of normal protein e. viruses that invade bacteria

d. misfolded versions of normal protein

If a bacterial cell is competent, it means that a. it is ready to undergo transduction b. the bacterium is ready to conjuget c. the bacterium is able to replicate its DNA and undergo cell fission d. the bacterium can import free DNA fragments from the environment e. two of the above are correct

d. the bacterium can import free DNA fragments from the environment

Transfer of DNA from a donor to a recipient as naked DNA in solution is a. conjugation b. transcription c. transduction d. transfromation e. translation

d. transformation

Prions vs. viroids: which statement is completely true? a. prions lack a capsid, viroids lack nucleic acid b. viroids contain DNA and RNA, prions have only RNA c. prion particles can increase in numbers, viroids cannot d. viroids require RNA polymerase to perpetuate themselves, prions do not e. prions would be susceptible to attack by restriction endonucleases, while viroids would not be f. none of the above are completely true

d. viroids require RNA polymerase to perpetuate themselves, prions do not

Which of the following is true regarding an Hfr strain? a. during conjugation, an F- recipient cell can receive part of the chromosome from an Hfr donor b. in general, conjugation with an Hfr strain does not typically convert the F- recipient to an F+ cell c. Hfr strains can be used to map the genes on the chromosome of the Hfr strain d. Hfr strains posses an F factor integrated into their chromosme e. all are true statements

e. all are true statements

For a certain bacterium, it has been found that a region of the chromosome designated "X" comprises a specific sequence of DNA nucleotides; this sequence can be converted into protein when the cells are grown on sucrose. Which of the following statements A-D is false regarding the information about this bacterium? a. the "X" phenotype is revealed when cells are grown on sucrose b. the conversion of the DNA sequence into a protein requires ribosomes c. "X" is a gene d. the first stage in converting the DNA sequence into a protein requires making an RNA copy of the X sequence e. none of A-D is false; all are true statements

e. none of A-D is false

Which statement among A-D is false regarding a bacteriophage in the lysogenic cycle? a. the bacteriophage can exit the lysogenic state depending on the condition of host cell b. while in this cycle, it would cause no harm to the host cell c. as the host cell divides, the bacteriophage genome will be present in all of the host's progeny d. it would become a prophage e. none of A-D is false

e. none of A-D is false

Which is true concerning viruses? a. there are a type of non-living cell that comes alive in a host b. they are generally 2-3 micrometers in size or greater c. they are generally capable of taking in nutrients and using them for energy d. all viruses contain DNA e. none of the above are true

e. none of the above are true

Various concentrations of the following: superoxide dismutase (SOD), catalase, peroxidase, or some combination of these is found in a. a facultative anaerobe b. an aerotolerant anaerobe c. an obligate aerobe d. a microaerophile e. one or more of these enzymes would be found in all of the above

e. one or more of these enzymes would be found in all of the above

Which viruses have single-stranded RNA that acts as a template for DNA synthesis? a. lytic phages b. DNA viruses c. viroids d. bacteriophages e. retroviruses

e. retroviruses

Genes for the capsid proteins are found in the: a. plasmid b. bacterial chromosome c. viral envelope d. ribosome e. viral genome

e. viral genome

E. coli is a normal inhabitant of the human gut; outside the body, it is capable of remaining viable for several hours at an elevated temperature around 45-46 C, though it does not grow while in this temperature range. Which of the following apply to this bacterium? a. it is a mesophile b. it is a thermophile c. it is thermotolerant d. a,b, and c are correct e. a and b are correct f. a and c are correct

f. a and c are correct

Which of the following is incorrectly matched? a. Genes: the transcription process copies these b. Ribosome: binds to a transcript c. Gene expression: the process of replicating a chromosome d. Codon table: represents DNA nucleotides e. Connects genotype to phenotype: different RNA-based molecules f. Two of A-E are incorrectly matched e. none of A-E are incorrectly matched

f. two are incorrectly matched (c, d)

Which of the following among A-E is not part of the life cycle of a lytic phage? a. the phage DNA is transcribed; the resulting mRNA is translated to make viral proteins b. it forms a prophage c. many copies of phage DNA are made d. assembly of virions occurs prior to exit e. the entire phage enters the host bacterial cell f. two of A-E are not part of the lytic cycle

f. two of A-E are not part of the lytic cycle (b. prophage is formed in they lysogenic cycle; e. only phage genome enters the host cell)

T/F: the term phenotype is used to describe all of the organism's genetic information

false

T/F Some viruses can infect multiple types of host organisms (animals, etc) and may also infect cells of different tissue types within a single host.

true

T/F: the sense strand of a particular gene would be identical to the mRNA for that gene, except uracil nucleotides would be substituted for thymine nucleotides in the mRNA.

true