Biology FSQs and Diagnostics (Class 4-6)
A single plasmid is isolated from bacterial cells. When the plasmid is digested with a restriction enzyme and then subjected to gel electrophoresis, two bands are observed on the gel. How many restriction sites for this enzyme are present in this plasmid? A) 2 B) 4 C) 1 D) 3
A) 2 -Plasmids are circular DNA, so if the plasmid is cut in two places it will produce two fragments. The general rule when cutting circular DNA with restriction enzymes is that the number of fragments you end up with is the same as the number of restriction sites.
A researcher is running a PCR experiment to amplify her DNA of interest. Assuming she starts with a single DNA molecule, after 30 rounds of PCR, how many DNA molecules would she have? A) 2^30 B) 2 x 30 C) 1 + 30^2 D) 30^2
A) 2^30
A pregnancy test is an ELISA set up to detect human chorionic gonadotropin (hCG), a hormone specific to pregnancy. How would this ELISA be configured? A) A primary antibody specific for hCG, blood or urine sample, a secondary antibody specific for hCG B) Blood or urine sample, a primary antibody specific for hCG, a secondary antibody specific for the primary antibody's constant region C) Blood or urine sample, a primary antibody specific for hCG, a secondary antibody specific for the primary antibody's antigen binding site D) A primary antibody specific for hCG, blood or urine sample, a secondary antibody specific for the primary antibody
A) A primary antibody specific for hCG, blood or urine sample, a secondary antibody specific for hCG
Which of the following provides the best description of diffusion? A) A solute moves passively down its concentration gradient in a thermodynamically favorable way, increasing entropy. B) A solute moves actively down its concentration gradient in a thermodynamically favorable way, increasing entropy. C) A solute moves passively down its concentration gradient in a thermodynamically favorable way, decreasing entropy. D) A solute moves actively down its concentration gradient in a thermodynamically favorable way, decreasing entropy.
A) A solute moves passively down its concentration gradient in a thermodynamically favorable way, increasing entropy.
What steps are necessary to replicate a (-)RNA virus? A) Create a (+)RNA copy of the genome using RNA-dependent RNA polymerase then replicate (-)RNA copies from that template using the same enzyme. B) Create a (+)RNA template using RNA-dependent DNA polymerase then replicate (-)RNA copies from that template using DNA-dependent RNA polymerase. C) Use RNA-dependent DNA polymerase to synthesize a DNA version of the genome and then replicate more RNA copies using the host cell's transcriptional machinery. D) Make more (-)RNA copies directly from the genome using RNA-dependent RNA polymerase.
A) Create a (+)RNA copy of the genome using RNA-dependent RNA polymerase then replicate (-)RNA copies from that template using the same enzyme.
As the level of cellular specialization increases, what cell cycle activity decreases? A) DNA replication B) Cell growth C) Genome packaging D) Genome transcription
A) DNA replication
Which of the following statements regarding the separation of proteins via gel electrophoresis is INCORRECT? A) Decreasing the percent of polyacrylamide makes the gel less dense and decreases the ability to resolve small distances between two proteins with similar molecular weights. B) Proteins with smaller molecular weights travel more quickly than those with higher molecular weights when an electric current is applied. C) Proteins travel in denatured states through the gel. D) Proteins migrate to the positive electrode of the gel apparatus because they become negatively charged during their preparation for electrophoresis.
A) Decreasing the percent of polyacrylamide makes the gel less dense and decreases the ability to resolve small distances between two proteins with similar molecular weights.
Conjugation can occur between bacterial cells of what status? A) F+ to F- B) F- to F+ C) F+ to F+ D) F- to F-
A) F+ to F-
A bacterial strain auxotrophic for lysine, isoleucine, and alanine production is mixed with an Hfr bacterial strain whose genome needs to be mapped. A sample taken after three minutes is able to grow on media supplemented with isoleucine and alanine. A sample taken after six minutes is able to grow on media supplemented with only isoleucine. A sample taken after nine minutes is able to grow on minimal media. What is the order of the amino acid synthesis genes on the Hfr strain? A) Lysine-Alanine-Isoleucine B) Lysine-Isoleucine-Alanine C) Isoleucine-Lysine-Alanine D) Alanine-Isoleucine-Lysine
A) Lysine-Alanine-Isoleucine
Which one of the following structures is found in bacterial cells? A) Ribosome B) Endoplasmic reticulum C) Nuclear membrane D) Mitochondrion
A) Ribosome
The nucleolus is a defined sub-region of the nucleus responsible for what cellular function? A) Ribosome subunit assembly B) Protein synthesis C) ATP production D) Lipid breakdown
A) Ribosome subunit assembly
Which of the following lab techniques is described by the following steps? Step 1: Separate DNA fragments on a gel Step 2: Transfer fragments to a nitrocellulose filter Step 3: Probe the filter for the target DNA sequence with hybridized probes A) Southern blotting B) ELISA C) Conjugation D) Radioimmunoassay
A) Southern blotting
*A geneticist testcrosses a dihybrid (heterozygous for two genes) mouse and notices the double dominant and double recessive phenotypes are present at 8% and 10% frequency, respectively. Which of the following is the best conclusion from these data? A) The dominant allele of one gene is linked to the recessive allele of the other, and the two genes are approximately 20 map units apart. B) The dominant alleles of the two genes are linked and the two genes are 80 map units apart. C) The recessive alleles of the two genes are approximately 20 map units apart and are not linked. D) The two genes are linked and 80 map units apart, but it cannot be determined which alleles are being inherited together.
A) The dominant allele of one gene is linked to the recessive allele of the other, and the two genes are approximately 20 map units apart.
*A virologist dips his pipette tip into a plaque on a bacterial plate, then into an actively growing culture of E. coli cells. A new strain of E. coli results. Which of the following best explains what occurred? A) The new E. coli strain is the result of transduction with a lysogenic phage. B) The new E. coli strain must have acquired random genomic mutations such as deamination. C) Antibiotics or toxins in the plaque exerted selective pressure on the bacterial culture. D) The plaque contained bacterial cells that underwent conjugation with the second culture.
A) The new E. coli strain is the result of transduction with a lysogenic phage.
The viral capsid: A) is made of protein and functions in attachment to the host. B) is coded for and translated by host machinery. C) is a complex mixture of amino acids and rRNA. D) can form many shapes and is composed of peptidoglycan.
A) is made of protein and functions in attachment to the host.
*All of the following statements about the cell membrane are true EXCEPT: A) lipid and protein content make up equivalent parts of cell membranes. B) as lipid saturation increases, lateral movement of proteins decreases. C) lipids and proteins move two-dimensionally, but do not tend to invert. D) D. lipids in the membrane can often be found grouped in structures called rafts.
A) lipid and protein content make up equivalent parts of cell membranes.
There are many structural similarities and differences between eukaryotic and prokaryotic cells. Which of the following cellular structures are the same whether isolated from a prokaryote or eukaryote? A) plasma membrane B) flagella C) ribosomes D) cell wall
A) plasma membrane
*Which of the following is a FALSE statement about (+) RNA viruses and (-) RNA viruses? A) Both types of viral genomes must encode an RNA-dependent polymerase. B) (+) RNA viruses must carry an RNA-dependent RNA polymerase. C) Viral proteins can be directly translated from a (+) RNA genome but not a (-) RNA genome. D) Injection of a (+) RNA genome into a host cell would result in infective activity.
B) (+) RNA viruses must carry an RNA-dependent RNA polymerase.
Which of the following is a best example of an opportunistic bacterial infection? A) Ulcers caused by Helicobacter pylori B) A Staphlycoccal infection in a wound C) A Streptococcal infection of the throat D) Food poisoning cause by exotoxins
B) A Staphlycoccal infection in a wound
A scientist has had a stationary-phase culture of E. coli at 4°C for several weeks. If she takes a small amount of this culture and puts it into 100 mL of new media (shaking at 37°C overnight), which of the following will be observed? A) The culture will immediately start growing exponentially and will be in the stationary phase by morning. B) After the lag phase, the culture will start growing rapidly. C) No bacterial growth will be observed because most of the original culture was dead. D) The culture will be mostly transparent in the morning, as the cells will be in stationary phase.
B) After the lag phase, the culture will start growing rapidly.
By what mechanism do bacteria reproduce? A) Transfection B) Binary fission C) Conjugation D) Transformation
B) Binary fission
How does standard DNA sequencing differ from running a polymerase chain reaction to synthesize DNA? A) PCR requires electrophoresis whereas DNA sequencing does not. B) DNA sequencing utilizes ddNTPs which lack the 3'OH group. This terminates polymerization, creating fragments. C) DNA sequencing is faster than PCR and yields higher copy numbers. D) PCR utilizes radiolabeling which would be deleterious in DNA sequencing.
B) DNA sequencing utilizes ddNTPs which lack the 3'OH group. This terminates polymerization, creating fragments.
A family pedigree is being constructed for the Laing family. The hairy ear phenotype is consistently passed from fathers to sons. Having dry ear wax has skipped a few generations, but affects Laing males and Laing females at the same frequency. Which of the following is most likely? A) Dry ear wax is an X-linked recessive trait and hairy ears is a mitochondrial trait. B) Dry ear wax is an autosomal recessive trait and hairy ears is Y-linked. C) Dry ear wax is an X-linked dominant trait and hairy ears is Y-linked. D) Dry ear wax is autosomal dominant and hairy ears is X-linked recessive.
B) Dry ear wax is an autosomal recessive trait and hairy ears is Y-linked.
A researcher hypothesizes that histone H2A.2 may have cytosolic functions. This hypothesis can best be tested by A) His-tagging H2A.2 and performing affinity chromatography B) GFP-tagging H2A.2 and performing fluorescent microscopy C) knocking down H2A.2 expression using siRNAs D) isolating H2A.2 and performing immunoprecipitation.
B) GFP-tagging H2A.2 and performing fluorescent microscopy
Which of the following is a hallmark of linkage? A) Linked genes function in similar cell processes and pathways. B) Linked alleles tend to be inherited together. C) Linked loci are found in similar locations on homologous chromosomes, but can be far apart on sister chromatids. D) Linked genes must be less than 50 map units apart on different chromosomes.
B) Linked alleles tend to be inherited together.
The bacterial flora of the gut is most likely characterized as which of the following? A) Mesophilic facultative aerobes B) Mesophilic obligate anaerobes C) Psychrophilic obligate aerobes D) Thermophilic tolerant anaerobes
B) Mesophilic obligate anaerobes
Which of the following is a true statement? A) The best way to increase evolutionary fitness is to have many offspring, regardless of whether they survive to adulthood. B) Natural selection acts on genetic diversity in populations and causes evolution. C) Changes in gene expression are the basis of evolution in populations. D) Divergent selection drives a population closer to the average trait.
B) Natural selection acts on genetic diversity in populations and causes evolution.
Shared characteristics between mitochondria and prokaryotes include which of the following? A) Internal organelles B) Possession of an electron transport system C) Mitosis D) Motility
B) Possession of an electron transport system
Which of the following degrades prions? A) Most proteases B) Prions are resistant to degradation C) Strong bases D) High heat
B) Prions are resistant to degradation
What type of enzyme is needed to replicate a viral genome composed of RNA? A) DNA-dependent RNA-polymerase B) RNA-dependent RNA-polymerase C) RNA-dependent DNA-polymerase D) DNA-dependent DNA-polymerase
B) RNA-dependent RNA-polymerase
During a polymerase chain reaction, high heat is used to denature and separate the DNA strands while cooling allows primers to anneal. Why does the extension step require additional heating? A) Nucleotides are synthesized only in high temperature conditions. B) The DNA polymerase used is heat sensitive and will not elongate in cooler conditions. C) Heat degrades the RNA primers so they do not become part of the permanent DNA sequence. D) Exonuclease activity requires elevated temperatures.
B) The DNA polymerase used is heat sensitive and will not elongate in cooler conditions.
A strain of bacterium was infected with a phage which caused all of the bacteria it infected to become resistant to the antibiotic streptomycin. Which of the following is the most likely explanation? A) he streptomycin resistance is conferred by a viral gene that allows the virus to replicate in the presence of antibiotic. B) The phage is lysogenic and carries a gene from other bacteria. C) The phage is lysogenic and alters the composition of the cell wall. D) When the phage inserts into the genome, it mutates the resistance gene.
B) The phage is lysogenic and carries a gene from other bacteria.
If an electrophoretic gel is placed in reverse, but the DNA samples are still loaded into the established wells, what will happen to the sample? A) The samples will still run down the gel, but the separation will not be as good since they will be running toward the negative electrode. B) The samples will run out of the back of the gel towards the positive electrode rather than down the length of the gel toward the negative electrode. C) The samples will separate based on density rather than weight. D) The samples will not run at all.
B) The samples will run out of the back of the gel towards the positive electrode rather than down the length of the gel toward the negative electrode.
Which of the following is LEAST characteristic of prions? A) They can be associated with gene mutations. B) They are not contagious. C) They are usually found in the nervous system. D) They are resistant to degradation by heat or chemicals.
B) They are not contagious.
Which of the following describes a mechanism by which a viroid can cause disease? A) The capsid of the viroid binds to the exterior of the cell and the DNA is injected into the cell. The viroid enters the lysogenic cycle, and is replicated along with the host genome. B) Viroids can serve as siRNAs that silence expression of genes that are necessary for cell function. C) Viroid RNA codes for abnormally folded proteins that cause host proteins to misfold as well. D) The capsid of the viroid binds to the exterior of the cell and the DNA is injected into the cell. The viroid enters the lytic cycle, and the cell bursts, releasing new viroids.
B) Viroids can serve as siRNAs that silence expression of genes that are necessary for cell function.
When running an ELISA to test for the presence of anti-chickenpox antibody in a patient's blood, which of the following would be bound to the microtiter well plate? A) primary anti-chickenpox antibody B) chickenpox antigen C) secondary anti-chickenpox antibody D) conjugated enzyme
B) chickenpox antigen
A membrane is impermeable to a solute, but the solute moves passively across the membrane, down its concentration gradient, using a specific integral membrane protein. This describes: A) simple diffusion B) facilitated diffusion C) primary active transport D) secondary active transport
B) facilitated diffusion
*The lytic and productive viral cycles are similar in that they both: A) destroy the host cell to allow viral particle release. B) involve a virus using host cellular machinery to replicate the viral genome and capsid. C) require the viral genome to be integrated into the host genome. D) involve expression of hydrolase to generate dNTP building blocks, and lysozyme to allow viral release.
B) involve a virus using host cellular machinery to replicate the viral genome and capsid.
The viral genome integrates into the host genome during the lysogenic cycle. After this: A) the host genome is not expressed, due to virus-encoded repressor proteins. B) the viral genome is silent, but replicated along with the host genome. C) the virus genome excises and activates once the host cell is dead or dying. D) excision of the viral genome is very precise and occurs only when the host cell is under stress.
B) the viral genome is silent, but replicated along with the host genome.
*During prophase II of meiosis: A) there are two chromatids per chromosome and the cell is diploid. B) there are two chromatids per chromosome and the cell is haploid. C) there is one chromatid per chromosome and the cell is diploid. D) there is one chromatid per chromosome and the cell is haploid.
B) there are two chromatids per chromosome and the cell is haploid.
Polydactyly (extra fingers or toes) is a congenital physical anomaly that can be caused by recessive or dominant alleles. It is found more frequently in blacks than in whites, and more frequently in men than in women. A study on autosomal recessive polydactyly in black women showed the incidence of this condition to be 10 in 1000 births. What is the frequency of the allele causing polydactyly in this population? A) 0.001 B) 0.01 C) 0.1 D) 1.0
C) 0.1
*Red-green colorblindness is an X-linked recessive trait in humans. If a carrier female mates with a normal male, what is the probability they will have a colorblind son? A) 0.75 B) 0.5 C) 0.25 D) 0.125
C) 0.25 If we assign D = normal and d = colorblind, the cross in the question stem is XDXd × XDY. The probability of receiving the colorblind allele from the mother is 0.5. The probability of receiving the Y chromosome from the father is 0.5. Therefore, the probability they will have a colorblind son is (0.5)(0.5) = 0.25.
Prions do not follow the principles of the Central Dogma and are referred to as self-replicating proteins. Which of the following best describes their means of replication? A) A disease-causing version of the protein recruits loaded and activated tRNAs to synthesize new prions. B) A regular version of the protein automatically becomes disease-causing when produced in neurons. C) A disease-causing version of the protein acts as the folding template to cause a regular version of the protein to become misshapen D) A regular version of the protein undergoes a nonsense mutation to induce a change to the disease-causing version.
C) A disease-causing version of the protein acts as the folding template to cause a regular version of the protein to become misshapen
Cytokinesis occurs during which two phases of mitosis? A) Prophase and metaphase B) Metaphase and anaphase C) Anaphase and telophase D) Telophase and prophase
C) Anaphase and telophase
HIV is a +RNA retrovirus whose genome can be directly translated to form a variety of viral proteins even before insertion into the host's genome. Which of the following enzymes would be needed AFTER insertion into the host genome to transcribe the mRNA for viral proteins? A) RNA dependent DNA polymerase B) DNA dependent DNA polymerase C) DNA dependent RNA polymerase D) RNA dependent RNA polymerase
C) DNA dependent RNA polymerase
Each of the following is true EXCEPT: A) PCR cycles through 3 temperatures: high temperature for template denaturing, low temperature for primer annealing and medium temperature for polymerization. B) During gel electrophoresis, negative DNA moves to the positive end of the gel in a size dependent manner. C) DNA is probed with DNA or RNA in a northern blot. D) Proteins are probed with antibodies in a western blot.
C) DNA is probed with DNA or RNA in a northern blot.
Which of the following is NOT a colligative property? A) Freezing point depression B) Boiling point elevation C) Diffusion D) Vapor pressure
C) Diffusion
Which of the following best describes primary active transport? A) Directly coupling the movement of a molecule down its concentration gradient to ATP hydrolysis B) Indirectly coupling the movement of a molecule down its concentration gradient to ATP hydrolysis C) Directly coupling the movement of a molecule against its concentration gradient to ATP hydrolysis D) Indirectly coupling the movement of a molecule against its concentration gradient to ATP hydrolysis
C) Directly coupling the movement of a molecule against its concentration gradient to ATP hydrolysis
A researcher isolates a microbe from the human gut. She determines that it has a thick cell wall, grows only in the absence of oxygen, and requires supplemental arginine. Which of the following is true about this microbe? A) It is an arg- Gram+ tolerant anaerobe. B) It is an arg- Gram- obligate anaerobe. C) It is an arg- Gram+ obligate anaerobe. D) It is an arg+ Gram- tolerant anaerobe.
C) It is an arg- Gram+ obligate anaerobe.
An experiment with a previously unidentified pathogen is done using guinea pigs and various means of inoculation are attempted. Within a few days, the guinea pigs begin to demonstrate a loss of coordination along with other neurological symptoms. Could the organism be a prion? A) Yes; loss of coordination is specific to prion infections B) No; prions don't infect guinea pigs C) No; the onset of symptoms was too rapid D) Yes; direct inoculation is required to contract a prion infection.
C) No; the onset of symptoms was too rapid
Which of the following would NOT be required to run a polymerase chain reaction (PCR)? A) Primers B) Taq DNA polymerase C) RNA polymerase D) Template DNA
C) RNA polymerase
How is a standard curve formulated for a radioimmunoassay? A) Unlabeled antigen is mixed with antibody followed by radiolabeled antigen and the increases in radioactivity are measured until they asymptotically level. B) Radiolabeled antigen and unlabeled antigen are simultaneously mixed with antibody and competitive binding determines the shape of the curve. C) Radiolabeled antigen is mixed with antibody followed by antigen without the radiolabel and the decrease in radioactivity is measured as the amount of unlabeled antigen increases. D) Radiolabeled antigen is mixed with antibody followed by antigen without the radiolabel and the transfer of radioactivity between them is measured.
C) Radiolabeled antigen is mixed with antibody followed by antigen without the radiolabel and the decrease in radioactivity is measured as the amount of unlabeled antigen increases.
Solution A is 1 M glucose. Solution B is 1 M NaCl. Which of the following is true? A) Solutions A and B have the same osmotic pressure. B) If the two solutions were placed on opposite sides of a semipermeable membrane, the volume of Solution A would increase. C) The boiling point elevation of Solution B is twice the boiling point elevation of Solution A. D) The freezing point depression of Solution A is twice the freezing point depression of Solution B.
C) The boiling point elevation of Solution B is twice the boiling point elevation of Solution A.
*If a Hfr cell mates with an F- bacterium, which of the following is true? A) Both cells will become Hfr strains. B) The Hfr bacterium becomes female (F-), while the female strain becomes Hfr. C) The female bacterium could end up female (F-), male (F+), or Hfr. D) The mating is impossible since only F+ bacteria (male) can perform conjugation with F- (female) cells.
C) The female bacterium could end up female (F-), male (F+), or Hfr.
A patient being treated with antibiotics for a severe bacterial infection appears to worsen when treatment begins, experiencing decreases in blood pressure. As treatment progresses, the infection resolves and the patient's blood pressure returns to normal. Why did the patient's condition degrade when starting treatment? A) The infection was likely cause by a strain of C. difficile that created a secondary opportunistic infection when the flora of the gut was eliminated by the antibiotic B) The infection was likely caused by a strain of E. coli that was removing 5' caps from host cell transcripts for use on its own. C) The infection was likely caused by a Gram-negative bacterium producing endotoxins. D) The infection was likely caused by a Gram-positive bacterium producing exotoxins.
C) The infection was likely caused by a Gram-negative bacterium producing endotoxins.
Which of the following is specific to an animal virus and NOT to a bacteriophage? A) Destruction of the host cell during the productive cycle B) Infection of the host cell occurs via penetration of genome through host cell membrane C) Uncoating of a genome from the capsid coat within the host cell cytoplasm D) Lysis of the cell membrane after the lytic cycle
C) Uncoating of a genome from the capsid coat within the host cell cytoplasm
A researcher is working with a certain strain of bacteria that will grow at 37°C, but only on plates that contain agar, glucose, arginine, and leucine. This organism can be classified as a(n): A) eukaryote B) psychrophile C) auxotroph D) thermophile
C) auxotroph
A researcher is making a transgenic mouse using gene targeted embryonic stem cells from a male black mouse, and a donor wild type morula from a brown mouse. This means that germline transmission of the targeted gene will most likely come from a: A) male chimeric mouse with mostly brown fur. B) female chimeric mouse with mostly black fur. C) male chimeric mouse with mostly black fur. D) female chimeric mouse with mostly brown fur.
C) male chimeric mouse with mostly black fur.
Both microarrays and flow cytometry involve labeling biological agents with fluorescent markers. These two techniques are different in that: A) microarrays give information on which proteins are expressed by a cell, while flow cytometry gives information on where fluorescent molecules are expressed in a tissue. B) microarrays give information on transcript levels, while flow cytometry gives information on where fluorescent molecules are expressed in a tissue. C) microarrays give information on transcript levels, while flow cytometry gives information on which fluorescent molecules are bound to individual cells. D) microarrays give information on which proteins are expressed by a cell, while flow cytometry gives information on which fluorescent molecules are bound to individual cells.
C) microarrays give information on transcript levels, while flow cytometry gives information on which fluorescent molecules are bound to individual cells.
Gut bacteria are most likely: A) facultative anaerobes B) obligate aerobes C) obligate anaerobes D) tolerant anaerobes
C) obligate anaerobes
A chemoheterotrophic bacteria that is a leucine auxotroph: A) makes its own food from organic molecules and can survive without leucine supplements. B) builds organic molecules from CO2 and must be given leucine supplements to survive. C) requires organic molecules as a carbon and energy source and cannot synthesize leucine. D) performs photosynthesis to obtain energy and can build organic molecules from glucose.
C) requires organic molecules as a carbon and energy source and cannot synthesize leucine.
A virologist is working to classify a new pathogen, and believes that it is a viroid. If the new pathogen is a viroid, an analysis of the pathogen should show that: A) the pathogen has a complex capsid B) the ratio of adenine to guanine in the genome is 1:1 C) the genome contains no thymine D) the genome codes for numerous proteins
C) the genome contains no thymine
Which of the following is NOT a means by which prion infection can typically occur? A) Inheritance B) Spontaneous mutation C) Consumption D) Aerosol contact
D) Aerosol contact
Which of the following is true regarding viral entry into a host cell? A) A. Viral attachment is relatively random, and this helps viruses evolve quickly. B) Attachment can also be called eclipse, and penetration can also be called adsorption. C) Prokaryotic viruses enter their host via receptor-mediated membrane fusion. D) Animal viruses can enter their host via endocytosis, but this requires a specific receptor on the host surface.
D) Animal viruses can enter their host via endocytosis, but this requires a specific receptor on the host surface.
Northern blotting could be used to explore all of the following EXCEPT: A) Retroviral genome B) Viroid C) Transcripts D) Bacterial genome
D) Bacterial genome
*Which of the following describes a trafficking pathway through the Golgi complex? A) Trans stack, medial stack, cis stack, anchor to cell membrane B) Pick up via endocytosis, cis stack, medial stack,trans stack C) Medial stack, cis stack, trans stack, release via exocytosis D) Cis stack, medial stack, trans stack, anchor to cell membrane
D) Cis stack, medial stack, trans stack, anchor to cell membrane
*Which of the following is an INACCURATE statement about bacterial cell structure? A) The peptidoglycan cell wall protects against osmotic pressure gradients. B) The 30S/50S ribosome performs translation in the cytoplasm. C) ATP synthesis occurs across the plasma membrane. D) Cyanobacteria have photosynthetic machinery in the chloroplast and cytoplasm
D) Cyanobacteria have photosynthetic machinery in the chloroplast and cytoplasm
In the creation of an expression vector, what step is necessary to prepare both a gene of interest and the plasmid that will carry it for ligation? A) Ensure both genetic pieces are single stranded. B) Treat both with proteases to avoid contaminating interactions from proteins. C) Allow exonucleases to proofread both sequences. D) Digest both genetic sequences with the same restriction endonuclease.
D) Digest both genetic sequences with the same restriction endonuclease.
What viral component is only derived from animal cells? A) Capsid B) DNA genome C) Surface proteins D) Envelope
D) Envelope
Which of the following has a vesicle fuse with the plasma membrane in order to release material from the cell? A) Phagocytosis B) Clathrin-coated pits C) Pinocytosis D) Exocytosis
D) Exocytosis
Eye color is a sex-linked trait in the fruit fly Drosophila melanogaster. A pure-breeding red-eyed female is mated with a pure-breeding white-eyed male. All offspring have red eyes. If an F1 female was backcrossed, which of the following would be observed in the F2? A) All female flies are red-eyed and all male flies are white-eyed. B) Half the female flies have white eyes and the other half have red eyes; all male flies have white eyes. C) All female flies are white-eyed and the males are 50% red-eyed and 50% white eyed. D) Half the flies have red eyes and half have white eyes, regardless of sex.
D) Half the flies have red eyes and half have white eyes, regardless of sex.
Short tandem repeat analysis for DNA fingerprinting utilizes patterns of repetitive DNA within what part of the genome to identify individuals? A) Exons B) Sex chromosomes C) Transposons D) Introns
D) Introns
Which of the following is NOT true about bacterial conjugation? A) It can be used to map the bacterial genome. B) It changes an F- "female" bacterium into an F+ "male" bacterium. C) It involves the transfer of either plasmid DNA, genomic DNA, or both, between two bacteria. D) It increases the genetic diversity and the size of a bacterial population.
D) It increases the genetic diversity and the size of a bacterial population.
Which of the following western blotting techniques correctly pairs the material used as a probe with the material being detected? A) Labeled nucleic acids are used to detect certain proteins. B) Labeled nucleic acids are used to detect certain nucleic acid sequences. C) Labeled antibodies are used to detect certain nucleic acid sequences. D) Labeled antibodies are used to detect certain proteins.
D) Labeled antibodies are used to detect certain proteins.
Viroids are circular pieces of single-stranded RNA, approximately 200-400 bases in length. What induces the folding of these subviral particles? A) Use of gyrase B) Formation of B-helices C) Double-bond linkages D) Many regions of self-complementarity
D) Many regions of self-complementarity
Methicillin-resistant Staphylococcus aureus (MRSA) has become a serious cause of skin infections both in the community and in the hospital. S. aureus are Gram-positive cocci that typically grow in clusters in culture. Which of the following is true? A) MRSA contain an outer membrane composed of a phospholipid bilayer B) MRSA cannot secrete exotoxin because of the presence of a thick cell wall. C) After gram-staining, the MRSA bacteria would appear as a light pink color under the microscope D) Methicillin functions to inhibit the transpeptidase enzyme used by bacteria to cross-link the peptides in the cell wall.
D) Methicillin functions to inhibit the transpeptidase enzyme used by bacteria to cross-link the peptides in the cell wall.
Certain nitrogen-fixing bacteria derive their nutrition from plants. The plants, in turn, benefit from the nitrogen that the bacteria supply. Which of the following best describes the relationship between the bacteria and the plants? A) Mimicry B) Commensalism C) Parasitism D) Mutualism
D) Mutualism
Symptoms of a prion disease can include problems with motor coordination and even with sleep. This indicates that the pathological protein is destroying what type of cell? A) Hair cells of the inner ear B) B cells capable of producing antibodies against it C) Skeletal muscle cells D) Neurons
D) Neurons
A researcher dissects testes from a mutant mouse and isolates individual gametes. Flow cytometry analysis shows that there are three populations of cells. Population I has 20 chromosomes, Population II has 19 chromosomes, and Population III has 21 chromosomes. Which of the following is most likely? A) The meiotic cells are unable to complete meiosis I. B) Mitosis of the spermatogonia is occurring very slowly. C) Nondisjunction in meiosis I resulted in an abnormal karyotype in gametes. D) Nondisjunction in anaphase II led to aneuploidy in some but not all gametes.
D) Nondisjunction in anaphase II led to aneuploidy in some but not all gametes.
During a Gram staining procedure, a bacterial culture does not appear as either Gram-positive or Gram-negative. What structural attribute could make bacteria appear Gram-indeterminate? A) Presence of a thick cell wall B) Presence of an outer lipid bilayer C) Presence of an inner lipid bilayer D) Presence of a cell wall with a waxy composition
D) Presence of a cell wall with a waxy composition
Which of the following transport mechanisms allow for infection of animal cells by viruses? A) Secondary active transport B) Simple diffusion C) Ligand-gated channels D) Receptor-mediated endocytosis
D) Receptor-mediated endocytosis
Scientists hypothesize that certain types of lung disease are the result of fragments of plasmid DNA being inserted into an exon of mRNA, leading to defective proteins. If a scientist identified a cell line that contained the mutant mRNA and they wanted to determine the actual base sequence of the mutation, which of the following techniques would be most useful in generating a large amount of genetic material to use for sequencing? A) Gas chromatography B) Induction of aberrant growth with Restriction Fragment Length Polymorphism (RFLP) analysis C) DNA fingerprinting D) Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)
D) Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)
*Mitochondria share what characteristic with prokaryotic cells? A) Presence of membrane-bound organelles B) Maternal inheritance pattern C) Lack of ribosomes D) Single chromosome
D) Single chromosome
Helicobacter pylori is a Gram-negative bacterium that causes gastric ulcers. Which of the following is FALSE about H. pylori? A) The cells have a periplasmic space containing the cell wall material. B) The cells contain endotoxins in the outer membrane. C) It affects the digestive system of humans. D) The H. pylori cells will look purple under the microscope after adding a dye such as crystal violet or methylene blue.
D) The H. pylori cells will look purple under the microscope after adding a dye such as crystal violet or methylene blue.
Black coat color is dominant to brown coat color in Labrador retrievers. A second gene (E or e) controls expression of the fur pigment gene, where the dominant allele allows pigment expression and the recessive allele prevents pigment expression. Labradors lacking black or brown pigment are referred to as "golden". If a dihybrid (heterozygous) male is bred to a homozygous recessive female, which of the following would be expected? A) The black lab and brown lab parents will have all black lab puppies. B) The black lab and golden lab parents will have black, brown, and golden puppies in approximately equal proportions. C) The black lab and brown lab parents will have half black and half golden puppies. D) The black lab and golden lab parents will have black, brown, and golden puppies, with golden coat color being the most common.
D) The black lab and golden lab parents will have black, brown, and golden puppies, with golden coat color being the most common.
What cellular processes can viroids exploit in order to replicate their genomes? A) Use of ribosomes B) Use of primase C) Use of DNA polymerase D) Use of transcriptional machinery
D) Use of transcriptional machinery
All viruses must: A) have an equal ratio of thymine:adenine B) have an envelope. C) code for DNA polymerase. D) have a capsid.
D) have a capsid.
All of the following processes occur in bacteria EXCEPT: A) electron transport B) regulation of transcription C) simultaneous transcription and translation D) mRNA processing
D) mRNA processing
Alpha tubulin and beta tubulin form dimers which are linked to form a protein sheet. This sheet is rolled into a tube which is the basis for a(n): A) intermediate tubule B) microfilament C) intermediate filament D) microtubule
D) microtubule
E. coli containing antibiotic resistance genes are commonly used in experiments. A researcher uses conjugation to add an ampicillin resistance gene via a strain of Hfr bacteria into the genome of the F- strain he's using. However, when he grows the new E. coli on an agar plate containing ampicillin, the bacteria don't grow. A reasonable explanation for this observation is that: A) he viral DNA containing the ampicillin resistance gene was unable to replicate after being injected. B) the bacteriophage successfully underwent recombination with the host cell but it did not have a full ampicillin resistance gene. C) the transformation of the ampicillin resistance gene was unsuccessful, so conjugation could not proceed. D) the sex pilus failed to form during conjugation, due to a mutation in the F factor.
D) the sex pilus failed to form during conjugation, due to a mutation in the F factor.
A researcher isolates Gram-negative bacilli bacteria. This organism has a: A) thick peptidoglycan cell wall and is spiral-shaped. B) thin chitin cell wall and is round-shaped. C) thick cellulose cell wall and is rod-shaped. D) thin peptidoglycan cell wall and is rod-shaped.
D) thin peptidoglycan cell wall and is rod-shaped.
*A researcher hypothesizes that the photic sneeze reflex (a condition where exposure to the sun causes uncontrollable sneezing) is due to a dominant autosomal allele. To test this hypothesis, he finds a family that has this trait in some individuals and not others, and generates a pedigree for analysis. To confirm his hypothesis, the researcher should look for: A) a pattern where two normal individuals have a child with photic sneeze reflex. B) two parents with photic sneeze reflex, that have only affected children. C) a testcross between two normal individuals with affected parents. D) two parents with photic sneeze reflex that have normal and affected offspring in a 1:3 ratio, respectively.
D) two parents with photic sneeze reflex that have normal and affected offspring in a 1:3 ratio, respectively.
A researcher cuts a thin slice of a fixed tissue, mounts it on a microscope slide and permeabilizes the cells. She can then: I. analyze the tissue by in situ hybridization, to determine where a transcript is found in the cell. II. analyze the tissue by immunohistochemistry to determine where a protein is found in the cell. III. perform Bradford quantification, using a UV-Vis spectrophotometer, to determine how much protein the cell contains.
I and II only
Which of the following are enzymes directly activated by G-protein linked receptors? I. Adenylate cyclase II. Phospholipase C III. Tyrosine kinase
I and II only
A researcher wants to clone a gene of interest into a plasmid. She plans on starting with genomic DNA, then cutting the gene of interest out. Then she plans on cutting open the plasmid and finally, ligating the gene into the plasmid. Which of the following will she need? I. Restriction endonuclease II. DNA ligase III. Taq polymerase
I and II only.
Which of the following is true about the differences in genome structure between eukaryotes and prokaryotes? I. A eukaryotic chromosome is linear and a prokaryotic chromosome is circular. II. In both eukaryotes and prokaryotes, DNA is wrapped around histone proteins to form a nucleosome. III. Prokaryotic genomes contain fewer repetitive sections than eukaryotic genomes.
I and III only. Item II is false: Eukaryotic chromosomes are linear and wrapped around histone proteins to form nucleosomes. Prokaryotic chromosomes are circular but are not wrapped around histone proteins.
A strain of bacteria is isolated which consumes oxygen during metabolism and utilizes carbon dioxide as its source of carbon. Which of the following descriptions could characterize this strain of bacteria? I. Obligate aerobe II. Autotroph III. Facultative anaerobe
I, II and III
Which of the following viruses should be able to reproduce successfully if they carry RNA-dependent RNA polymerase into their host cell? I. (+) RNA virus II. (-) RNA virus III. dsDNA virus
I, II, and III
Coronaviruses are enveloped, +RNA viruses that typically cause respiratory infections. A coronavirus was implicated in the SARS epidemic of 2002. Which of the following statements are true about Coronavirus? I. They can be cultured in any type of cell as long as an RNA dependent RNA polymerase is included. II. They can be cultured in animal cells. III. Their genome likely has a poly-A tail.
II and III only.
*Which of the following could lead to cancer? I. An overexpression of initiator caspases, leading to apoptosis II. A mutation in the tumor suppressor gene p53 that prevents the expression of the p53 protein. III. A mutation in the protooncogene Ras that prevents the expression of the Ras protein
II only.
