Quiz Questions for ALL CHAPTERS
During respiration, energy is retrieved from the high-energy bonds found in certain organic molecules. Which of the following, in addition to energy, are the ultimate products of respiration? Question 14 options: A) CO2, H2O B) CH3, H2O C) CH2OH, O2 D) CO2, O2
A
Hydrolytic enzymes typically have low functionality outside of the lysosome due to _____________. Question 103 options: A) A requirement for a lower pH than that in the cytosol B) Allosteric inhibition by ATP found in the cytosol C) The higher rate of UV damage from light in the cytosol D) The highly oxidizing environment of the cytosol Save
A) A requirement for a lower pH than that in the cytosol
While in your cell biology lab, you discover a chemical that causes cells to skip G1 and G2 phases (like a frog egg). The cells perform S phase and mitosis as normal. Which of the following would you most likely observe in cells after exposure to the chemical? Question 122 options: A) After cell division, daughter cells would be smaller than normal. B) After cell division, daughter cells would be larger than normal. C) After cell division, daughter cells would contain only half of the normal amount of DNA. D) After cell division, daughter cells would contain twice the amount of DNA.
A) After cell division, daughter cells would be smaller than normal.
Individual intermediate filament proteins dimerize through coiled-coil interactions. What protein structural feature takes part in this interaction? Question 114 options: A) Alpha-helix B) Beta-sheet C) Zinc finger motif D) Sarc homology domain
A) Alpha-helix
Why is an excess of normal deoxyribonucleoside triphosphate molecules (dNTPs) needed during dideoxy sequencing? Question 63 options: A) DNA polymerase uses the dNTPs to synthesize a DNA molecule complementary to the molecule being sequenced. B) dNTPs are consumed as energy to fuel the sequencing reactions. C) When dNTP levels are too low, there will be very few chain-termination events. D) The dNTPs can hybridize to the fragment to be sequenced and serve as primers for DNA polymerase.
A) DNA polymerase uses the dNTPs to synthesize a DNA molecule complementary to the molecule being sequenced.
Genes/alleles found close together on the same chromosome often segregate together and are said to be linked. However, if the genes are far apart on the same chromosome, they behave as if they are segregate independently. Why? Question 125 options: A) Genes far apart have a higher likelihood of crossover events occuring between them. B) Transposons preferentially target linked genes C) Chromosome dissassembly will shuffle the genes around. D) Apoptosis will the degrade unlinked genes
A) Genes far apart have a higher likelihood of crossover events occuring between them.
Which option best describes the role of fermentation? Question 84 options: A) In the absence of oxygen, fermentation allows the regeneration of NAD+ and continued activity of glycolysis and ATP production. B) Fermentation serves to produce ethanol for entry into the citric acid cycle. C) Fermentation oxidizes NADH for use in oxidative phosphorylation. D) Fermentation is a precursor reaction to glycogen formation.
A) In the absence of oxygen, fermentation allows the regeneration of NAD+ and continued activity of glycolysis and ATP production.
Cell-surface receptors generally fall into 3 main classes. Which of the following is not one of those classes? Question 106 options: A) MAP kinase B) Ion-channel coupled C) G-protein coupled D) Enzyme coupled
A) MAP kinase
Transport of a protein into which subcellular compartment would not require the protein to be unfolded? Note: due to an error, there are two potential correct answers here. Question 98 options: A) Nucleus B) Chloroplast C) Mitochondrion D) Peroxisome
A) Nucleus and D.) Peroxisome
Porin proteins form large, barrel-like channels in the membrane. Which of the following is not true about these channels? Question 71 options: A) They are made primarily of α helices. B) They are made primarily of β sheets. C) They cannot form narrow channels. D) They have alternating hydrophobic and hydrophilic amino acids.
A) They are made primarily of α helices.
Which of the following channels would not be expected to generate a change in voltage by movement of its substrate across the membrane where it is found? Question 73 options: A) an aquaporin B) a sodium channel C) a calcium channel D) a proton channel
A) an aquaporin
Electrons generally travel from a molecule with ________ to a molecule with _________ . Question 91 options: A) low redox potential / high redox potential B) high redox potential / low redox potential
A) low redox potential / high redox potential
Which type of lipids are the most abundant in the plasma membrane? Question 66 options: A) phospholipids B) glycolipids C) sterols D) triacylglycerides
A) phospholipids
Proteins are directed to their proper compartments by _____________. Question 99 options: A) signal sequences B) promoter regions C) introns D) Chaperones
A) signal sequences
Transporters, in contrast to channels, work by ________________. Question 75 options: A) specific binding to solutes. B) a gating mechanism. C) filtering solutes by charge. D) filtering solutes by size.
A) specific binding to solutes.
Which of the following statements is FALSE? Question 10 options: A) Photosynthetic organisms release only O2 into the atmosphere, while nonphotosynthetic organisms release only CO2. B) The cycling of carbon through the biosphere first requires the incorporation of inorganic CO2 into organic molecules. C) The oxidation of one molecule is always coupled to the reduction of a second molecule. D) During cellular respiration, carbon-containing molecules become successively more oxidized until they reach their most oxidized form, as CO2. Save
A.
Which sentence best describes the occurance of genes on a chromosome? Question 23 options: Genes may be on either strand of the chromosome. The majority of genes on a chromosome occur on only one strand, named the coding strand The genetic information for one RNA molecule is encoded on both strands Organisms with more genes are always more complex
A. Genes may be on either strand of the chromosome.
DNA polymerase catalyzes the joining of a nucleotide to a growing DNA strand. What prevents this enzyme from catalyzing the reverse reaction? Question 27 options: A) hydrolysis of pyrophosphate (PPi) to inorganic phosphate (Pi) + Pi B) release of PPi from the nucleotide C) hybridization of the new strand to the template D) loss of ATP as an energy source
A. Hydrolysis of pyrophosphate (PPi) to inorganic phosphate (Pi)+Pi
The amino acids glutamine and glutamic acid are shown in the figure. They differ only in the structure of their side chains (circled). At pH 7, glutamic acid can participate in molecular interactions that are not possible for glutamine. What types of interactions are these? Question 6 options: A) ionic bonds B) hydrogen bonds C) van der Waals interactions D) covalent bonds
A. Ionic Bonds
Methylation and acetylation are common changes made to histone H3, and the specific combination of these changes is sometimes referred to as the "histone code." Which of the following patterns will probably lead to gene silencing? Question 21 options: lysine 9 methylation lysine 4 methylation and lysine 9 acetylation lysine 14 acetylation lysine 9 acetylation and lysine 14 acetylation
A. Lysine 9 methylation
In most cytoskeletal filament proteins, growth of the filament is fastest at the __________ end. Question 113 options: Plus Minus Capped GDP-associated
A. Plus
Transcription in bacteria differs from transcription in a eukaryotic cell because __________________________. Question 35 options: A) RNA polymerase (along with its sigma subunit) can initiate transcription on its own. B) RNA polymerase (along with its sigma subunit) requires the general transcription factors to assemble at the promoter before polymerase can begin transcription. C) the sigma subunit must associate with the appropriate type of RNA polymerase to produce mRNAs. D) RNA polymerase must be phosphorylated at its C-terminal tail for transcription to proceed.
A. RNA polymerase (along with its sigma subunit) can initiate transcription on its own.
Sometimes, chemical damage to DNA can occur just before DNA replication begins, not giving the repair system enough time to correct the error before the DNA is duplicated. This gives rise to mutation. If the cytosine in the sequence TCAT is deaminated and not repaired, which of the following is the point mutation you would observe after this segment has undergone two rounds of DNA replication? Question 31 options: A) TTAT B) TUAT C) TGAT D) TAAT
A. TTAT
Which of the following statements is false? Question 48 options: A) A mutation that arises in a mother's somatic cell often causes a disease in her daughter. B) All mutations in an asexually reproducing single-celled organism are passed on to progeny. C) In an evolutionary sense, somatic cells exist only to help propagate germ-line cells. D) A mutation is passed on to offspring only if it is present in the germ line.
A. a mutation that arises in a mother's somatic cell often causes a disease in her daughter.
Which of the following statements about transcriptional regulators is false? Question 41 options: A) Transcriptional regulators usually interact with the sugar-phosphate backbone on the outside of the double helix to determine where to bind on the DNA helix. B) Transcriptional regulators will form hydrogen bonds, ionic bonds, and hydrophobic interactions with DNA. C) The DNA-binding motifs of transcriptional regulators usually bind in the major groove of the DNA helix. D) The binding of transcriptional regulators generally does not disrupt the hydrogen bonds that hold the double helix together. Save
A. transcriptional regulators usually interat with the sugar-phosphate backbone on the outside of the double helix to determine where to bind on the DNA helix.
The potential energy stored in high-energy bonds is commonly harnessed when the bonds are split by the addition of _______________ in a process called _____________. Question 13 options: A) ATP, phosphorylation. B) water, hydrolysis. C) hydroxide, hydration. D) acetate, acetylation.
B
The citric acid cycle catalyzes the complete oxidation of acetyl groups. This completely oxidized molecule is ______________. Question 86 options: A) CH4 B) CO2 C) NADH D) FADH2
B) CO2
Which family of proteases are largely responsible for apoptosis? Question 121 options: A) Lysozymes B) Caspases C) Trypsins D) Phospholipases
B) Caspases
The reduction of NAD+ during glycolysis is catalyzed by which family of enzymes? Question 82 options: A) Isomerase B) Dehydrogenase C) Kinase D) Mutase
B) Dehydrogenase
hich of the following is not true of receptor tyrosine kinases (RTKs)? Question 110 options: A) Binding of a signal molecule triggers dimerization of the RTK B) Dimerization triggers recruitment of other kinase proteins that phosphorylate the RTK C) Phosphorylated RTKs serve as docking sites for signaling proteins D) They are a transmembrane protein with their ligand binding site facing the extracellular space.
B) Dimerization triggers recruitment of other kinase proteins that phosphorylate the RTK
The sarcoplasmic reticulum is a specialized region of the _____________ that contains a high concentration of ________. Question 112 options: A) Endoplasmic Reticulum (ER) / K+ ions B) ER / Ca2+ ions C) Endosome / lysozyme D) Golgi / phospholipids
B) ER / Ca2+ ions
Which best describes the general pathway for protein excretion, starting from synthesis and moving outward? Question 101 options: A) Trans Golgi network, Cis Golgi network, ER, plasma membrane B) ER, cis Golgi network, trans Golgi network, plasma membrane C) ER, trans Golgi network, cis Golgi network, plasma membrane D) Cis Golgi network, ER, Trans Golgi network, plasma membrane
B) ER, cis Golgi network, trans Golgi network, plasma membrane
The activity of ATP synthase is reversible. When ATP concentrations in the mitochondrion are high, which function will ATP synthase perform? Question 90 options: A) Oxidize NADH to NAD+ to bring electrons into the electron transport chain B) Hydrolize ATP to pump H+ ions across the inner membrane C) Oxidize H2O to form O2 D) Reduce NADP+ to NADPH
B) Hydrolize ATP to pump H+ ions across the inner membrane
Which of the following best describes the behavior of a gated channel? Question 76 options: A) It stays open continuously when stimulated. B) It opens more frequently in response to a given stimulus. C) It opens more widely as the stimulus becomes stronger. D) It remains closed if unstimulated.
B) It opens more frequently in response to a given stimulus.
Cells use membranes to help maintain set ranges of ion concentrations inside and outside the cell. Which of the following ions is the most abundant inside a typical mammalian cell? Question 74 options: A) Na+ B) K+ C) Ca2+ D) Cl- Save
B) K+
You cut a vector using the PciI restriction nuclease. Which of the following restriction nucleases will generate a fragment that can be ligated into this cut vector with the addition of only ligase and ATP? Use the figure below, which shows recognition and cleavage sites of several restriction enzymes. Question 59 options: A) HindIII B) NcoI C) MmeI D) NspV
B) NcoI
Which of the following statements about PCR is false? Question 61 options: A) PCR uses a DNA polymerase from a thermophilic bacterium. B) PCR is particularly powerful because after each cycle of replication, there is a linear increase in the amount of DNA available. C) For PCR, every round of replication is preceded by the denaturation of the double-stranded DNA molecules. D) The PCR will generate a pool of double-stranded DNA molecules, most of which will have DNA from primers at the 5′ ends.
B) PCR is particularly powerful because after each cycle of replication, there is a linear increase in the amount of DNA available.
A cell releases a signalling molecule into its surrounding extracellular fluid which diffuses to nearby cells. This best describes which form of extracellular signalling? Question 109 options: A) Endocrine B) Paracrine C) Synaptic D) Contact-dependent
B) Paracrine
A bacterium is suddenly expelled from a warm human intestine into the cold world outside. Which of the following adjustments might the bacterium make to maintain the same level of membrane fluidity? Question 69 options: A) Produce lipids with hydrocarbon tails that are longer and have fewer double bonds. B) Produce lipids with hydrocarbon tails that are shorter and have more double bonds. C) Decrease the amount of cholesterol in the membrane. D) Decrease the amount of glycolipids in the membrane.
B) Produce lipids with hydrocarbon tails that are shorter and have more double bonds.
Electron transfer is a potentially dangerous process due to the potential formation of ________. Question 93 options: A) ATP B) Reactive oxygen species (superoxide radicals) C) antioxidants D) uncouplers
B) Reactive oxygen species (superoxide radicals)
Which of the following statements about restriction nucleases is false? Question 57 options: A) A reproducible set of DNA fragments will be produced every time a restriction nuclease digests a known piece of DNA. B) Restriction nucleases recognize specific sequences on single-stranded DNA. C) Some bacteria use restriction nucleases as protection from foreign DNA. D) Some restriction nucleases cut in a staggered fashion, leaving short, single-stranded regions of DNA at the ends of the cut molecule.
B) Restriction nucleases recognize specific sequences on single-stranded DNA.
Which of the following statements about prokaryotic mRNA molecules is false? Question 39 options: A) A single prokaryotic mRNA molecule can be translated into several proteins. B) Ribosomes must bind to the 5′ cap before initiating translation. C) mRNAs are not polyadenylated. D) Ribosomes can start translating an mRNA molecule before transcription is complete.
B) Ribosomes must bind to the 5′ cap before initiating translation.
Consider the reformation of the nucleus at telophase. How do nuclear proteins become properly re-sorted so that the new nucleus contains only nuclear proteins? *See Question 18-7 in the text Question 118 options: A) The new nucleus reforms and mis-localized cytosolic proteins are transported out. B) The new nuclear envelope reforms on chromosomes, preventing cytosolic proteins from being localized to the nucleus. Nuclear proteins are then imported into the nucleus. C) Phosphorylation of cytosolic proteins during prometaphase flags them for degredation if they become trapped in the reforming nucleus at telophase. D) The nucleus reforms, entrapping both cytosolic and nuclear proteins. Gradually over time cytosolic proteins will become damaged and degraded, eventually leading to only nuclear proteins in the nucleus.
B) The new nuclear envelope reforms on chromosomes, preventing cytosolic proteins from being localized to the nucleus. Nuclear proteins are then imported into the nucleus.
The number of distinct protein species found in humans and other organisms can vastly exceed the number of genes. This is largely due to ______________. Question 56 options: A) protein degradation. B) alternative splicing. C) homologous genes. D) mutation.
B) alternative splicing.
Which of the following is not an example of a secondary messenger? Question 105 options: A) cAMP B) receptor tyrosine kinase (RTK) C) Inositol phospholipid D) Ca2+
B) receptor tyrosine kinase (RTK)
Which of the following DNA sequences is not commonly carried on a DNA-only transposon? Question 54 options: A) transposase gene B) reverse transcriptase gene C) recognition site for transposase D) antibiotic-resistance gene
B) reverse transcriptase gene
How many replication forks are formed when an origin of replication is opened? Question 26 options: A) 1 B) 2 C) 3 D) 4
B. 2
Homologous recombination is an important mechanism in which organisms use a "backup" copy of the DNA as a template to fix double-strand breaks without loss of genetic information. Which of the following is not necessary for homologous recombination to occur? Question 32 options: A) 3′ DNA strand overhangs B) 5′ DNA strand overhangs C) a long stretch of sequence similarity D) nucleases
B. 5' DNA strand overhangs
Which of the following statements about RNA splicing is false? Question 36 options: A) Conventional introns are not found in bacterial genes. B) For a gene to function properly, every exon must be removed from the primary transcript in the same fashion on every mRNA molecule produced from the same gene. C) Small RNA molecules in the nucleus perform the splicing reactions necessary for the removal of introns. D) Splicing occurs after the 5′ cap has been added to the end of the primary transcript.
B. For a gene to fuunction properly, every exon must be removed from the primary transcript in the same fashion on every mRNA molecule produced from the same gene.
When elemental sodium is added to water, the sodium atoms ionize spontaneously. Uncharged Na becomes Na+. This means that the Na atoms have been _____________. Question 9 options: A) protonated B) oxidized C) hydrogenated D) reduced
B. Oxidized
Because hydrogen bonds hold the two strands of a DNA molecule together, the strands can be separated without breaking any covalent bonds. Every unique DNA molecule "melts" at a different temperature. In this context, Tm (melting temperature) is the point at which two strands separate, or become denatured. Which DNA sequence listed below do you predict to have the lowest relative melting temperatures (Tm). Assume that they all begin as stable double-stranded DNA molecules. Question 18 options: GGCGCACC TATTGTCT GACTCCTG CTAACTGG
B. TATTGTCT
Which of the following statements about sequence proofreading during DNA replication is false? Question 29 options: A) The exonuclease activity is in a different domain of the DNA polymerase. B) The exonuclease activity cleaves DNA in the 5′-to-3′ direction. C) The DNA proofreading activity occurs concomitantly with strand elongation. D) If an incorrect base is added, it is "unpaired" before removal.
B. The exonuclease activity cleaves DNA in the 5'to 3' direction.
snRNAs ___________________. Question 37 options: A) are translated into snRNPs. B) are important for producing mature mRNA transcripts in bacteria. C) are removed by the spliceosome during RNA splicing. D) can bind to specific sequences at intron-exon boundaries through complementary base-pairing.
B. are important for producing mature mRNA transcripts in bacteria.
How are most eukaryotic transcription regulators able to affect transcription when their binding sites are far from the promoter? Question 44 options: by binding to their binding site and sliding to the site of RNA polymerase assembly by looping out the intervening DNA between their binding site and the promoter by unwinding the DNA between their binding site and the promoter by attracting RNA polymerase and modifying it before it can bind to the promoter
B. by looping out the intervening DNA between their binding site and the promoter.
Which of these method(s) of controlling eukaryotic gene expression is NOT employed in prokaryotic cells? Question 40 options: A) controlling how often a gene is transcribed B) controlling how an RNA transcript is spliced C) controlling which mRNAs are translated into protein by the ribosomes D) controlling how rapidly proteins are destroyed once they are made
B. controlling how an RNA transcript is spliced.
Combinatorial control of gene expression __________________________. Question 45 options: A) involves every gene using a different combination of transcriptional regulators for its proper expression. B) involves groups of transcriptional regulators working together to determine the expression of a gene. C) involves only the use of gene activators used together to regulate genes appropriately. D) is seen only when genes are arranged in operons.
B. involves groups of transcriptional regulators working together to determine the expression of a gene.
What do you predict would happen if you replace the Lac operator DNA from the Lac operon with the DNA from the operator region from the tryptophan operon? (Figures 8-7 and 8-9 from the text may be helpful) Question 43 options: A) The presence of lactose will not cause allosteric changes to the Lac repressor. B) The Lac operon will not be transcribed when tryptophan levels are high. C) The lack of glucose will no longer allow CAP binding to the DNA. D) RNA polymerase will only bind to the Lac promoter when lactose is present. Save
B. the Lac operon will not be transcribed when tryptophan levels are high
Mitochondria perform cellular respiration, a process that uses oxygen, generates carbon dioxide, and produces chemical energy for the cell. Which answer below indicates a correct pairing of material "burned" and the form of energy produced during cellular respiration? Question 1 options: A) fat, ADP B) sugar, fat C) sugar, ATP D) fat, protein
C
You are a virologist interested in studying the evolution of viral genomes. You are studying two newly isolated viral strains and have sequenced their genomes. You find that the genome of strain 1 contains 25% A, 55% G, 20% C, and 10% T. You report that you have isolated a virus with a single-stranded DNA genome. Based on what evidence can you make this conclusion? Question 16 options: single-stranded genomes always have a large percentage of purines using the formula: G - A = C + T Double-stranded genomes have equal amounts of A and T Single-stranded genomes have a higher rate of mutation
C
__________ are fairly small organelles that provide a safe place within the cell to carry out certain biochemical reactions that generate harmful, highly reactive oxygen species. These chemicals are both generated and broken down in the same location. Question 2 options: A) Nucleosomes B) Lysosomes C) Peroxisomes D) Endosomes
C
Genetic diversity in meiosis derives from ______________. Question 127 options: A) The independent assortment of maternal and paternal homologs B) Crossing-over shuffling alleles C) Both A and B D) There is no genetic diversity created during meiosis, all haploid gametes produced are genetically identical
C) Both A and B
A diploid organism has a maternal and paternal copy of each chromosome. As a set, these are called ____________________. Question 126 options: A) Sister chromatids B) Hardy-Weinberg pairs C) Homologous chromosomes (homologs) D) Kinetochores
C) Homologous chromosomes (homologs)
t is thought that mitochondria and chloroplasts were once free-living organisms. Which of the following is not evidence of their once free-living evolutionary origins? (Which statement is false?) Question 95 options: A) Mitochondria and chloroplasts have their own DNA, separate from that of the cellular genome. B) Mitochondria and chloroplasts have their own ribosomes, structurally different from those in the cellular cytosol. C) If isolated from the cell, mitochondria and chloroplasts remain viable (can survive, replicate, and metabolize as free-living organisms). D) Mitochondria and chloroplasts replicate through binary fision, similar to bacteria.
C) If isolated from the cell, mitochondria and chloroplasts remain viable (can survive, replicate, and metabolize as free-living organisms).
Which of the following is NOT required in order to activate a Cdk? Question 120 options: A) It must bind its respective cyclin. B) It must have received an activating phosphorylation. C) It must be ubiquitylated. D) It must have its inhibitory phosphates removed.
C) It must be ubiquitylated.
Which of the following statements is true? Question 68 options: A) Phospholipids will spontaneously form liposomes in nonpolar solvents. B) A bacterium is suddenly expelled from a warm human intestine into the cold world outside. Which of the following adjustments might the bacterium make to maintain the same level of membrane fluidity? In eukaryotes, all membrane-enclosed organelles are surrounded by one lipid bilayer. C) Membrane lipids diffuse within the plane of the membrane. D) Membrane lipids frequently flip-flop between one monolayer and the other.
C) Membrane lipids diffuse within the plane of the membrane.
Which statement concerning protein glycosylation is true? Question 102 options: A) Protein glycosylation starts in the Golgi apparatus B) Protein glycosylation usually occurs on the cytosolic side of the ER C) Most glycosylated proteins start with a universal 14-sugar oligosaccharide which is later modified D) In the ER, sugars are added one at a time to the protein, until the protein obtains its final sugar structures.
C) Most glycosylated proteins start with a universal 14-sugar oligosaccharide which is later modified
The six carbon molecule fructose 1,6-bisphosphate is cleaved into which two 3-carbon molecules. Question 87 options: A) Two molecules of dihydroxyacetone phosphate (DHAP) B) Two molecules of glyceraldehyde 3-phosphate (G3P) C) One molecule of DHAP and one molecule of G3P D) Two molecules of pyruvate
C) One molecule of DHAP and one molecule of G3P
HIV is a human retrovirus that integrates into the host cell's genome and will eventually replicate, produce viral proteins, and ultimately escape from the host cell. Which of the following proteins is not encoded in the HIV genome? Question 55 options: A) reverse transcriptase B) envelope protein C) RNA polymerase D) capsid protein
C) RNA polymerase
Which statement best defines anabolic reactions? Question 88 options: A) The sum total of chemical reactions in an organism. B) Reactions that lead to the generation of smaller molecules from macromolecules. C) Reactions that lead to the generation of macromolecules from small molecules. D) Reactions that predominate during anaerobic conditions.
C) Reactions that lead to the generation of macromolecules from small molecules.
When the net charge on either side of the plasma membrane is zero, what else is true? Question 78 options: A) There is an equal number of K+ ions on each side of the plasma membrane. B) The K+ leak channels are open. C) The electrochemical potential across the membrane is zero. D) The resting membrane potential is between -20 mV and -200 mV.
C) The electrochemical potential across the membrane is zero.
Which statement best describes why cells resulting from meiosis are haploid, rather than diploid? (Stated differently: Which of the following statements are true regarding meiosis?) Question 124 options: A) There is no genome duplication (S phase) in meiosis B) One set of each chromosome, maternal or paternal, are enzymatically degraded during meiosis, resulting in half of the genome being present. C) There is an additional cell division phase in meiosis. D) Crossing over events cause the formation of micro-chromosomes in vesicles which bud off to form haploid gametes.
C) There is an additional cell division phase in meiosis.
New membrane phospholipids are synthesized by enzymes bound to the _____________ side of the _________________ membrane. Question 70 options: A) cytosolic, mitochondrial B) luminal, Golgi C) cytosolic, endoplasmic reticulum D) extracellular, plasma
C) cytosolic, endoplasmic reticulum
The electrons transported in the photosynthetic electron transport chain are obtained from _________. Question 92 options: A) Light B) Antenna complex chlorophyll molecules C) the special pair of chlorophyll molecules D) NADPH
C) the special pair of chlorophyll molecules
You create a recombinant DNA molecule that fuses the coding sequence of green fluorescent protein to the regulatory DNA sequences that control the expression of your favorite genes. Which of the following pieces of information can you NOT gain by examining the expression of this reporter gene? NOTE: this is not a GFP fusion protein. Instead, GFP is under the expression of your favorite gene's promoter. It is acting as a reporter gene. Question 65 options: A) the tissue where the protein encoded by this gene is expressed B) the cell in which the protein encoded by this gene is expressed C) the specific location within the cell of the protein encoded by this gene D) when, during an organism's development, this gene is expressed
C) the specific location within the cell of the protein encoded by this gene
Beside the distortion in the DNA backbone caused by a mismatched base pair, what additional mark is there on eukaryotic DNA to indicate which strand needs to be repaired? Question 30 options: A) a nick in the template strand B) a chemical modification of the new strand C) a nick in the new strand D) a sequence gap in the new strand
C. A nick in the new strand
DNA replication is considered semiconservative because ____________________________. Question 25 options: A) after many rounds of DNA replication, the original DNA double helix is still intact. B) each daughter DNA molecule consists of two new strands copied from the parent DNA molecule. C) each daughter DNA molecule consists of one strand from the parent DNA molecule and one new strand. D) new DNA strands must be copied from a DNA template.
C. Each daughter DNA molecule consists of one strand from the parent DNA molecule and one new strand.
The core histones are small, basic proteins that have a globular domain at the C-terminus and a long, extended conformation at the N-terminus. Which of the following is not true of the N-terminal "tail" of these histones? Question 20 options: It is subject to covalent modifications. It extends out of the nucleosome core. It binds to DNA in a sequence-specific manner. It helps DNA pack tightly.
C. It binds to DNA in a sequence-specific manner
RNA in cells differs from DNA in that ___________________. Question 33 options: A) it contains the base uracil, which pairs with cytosine. B) it is single-stranded and cannot form base pairs. C) it is single-stranded and can fold up into a variety of structures. D) the sugar ribose contains fewer oxygen atoms than does deoxyribose. Save
C. It is single-stranded and can fold up into a variety of structures
The ribosome is important for catalyzing the formation of peptide bonds. Which of the following statements is true? Question 38 options: A) The number of rRNA molecules that make up a ribosome greatly exceeds the number of protein molecules found in the ribosome. B) The large subunit of the ribosome is important for binding to the mRNA. C) The catalytic site for peptide bond formation is formed primarily from an rRNA. D) Once the large and small subunits of the ribosome assemble, they will not separate from each other until degraded by the proteasome.
C. The catalytic site for peptide bond formation is formed primarily from an rRNA
The process of sorting human chromosome pairs by size and morphology is called karyotyping. A modern method employed for karyotyping is called chromosome painting. How are individual chromosomes "painted"? Question 19 options: with a laser using fluorescent antibodies using fluorescent DNA molecules using green fluorescent protein Save
C. Using fluorescent DNA Molecules
Although the chromatin structure of interphase and mitotic chromosomes is very compact, DNA-binding proteins and protein complexes must be able to gain access to the DNA molecule. Chromatin-remodeling complexes provide this access by __________________. Question 22 options: recruiting other enzymes. modifying the N-terminal tails of core histones. using the energy of ATP hydrolysis to move nucleosomes. denaturing the DNA by interfering with hydrogen-bonding between base pairs. Save
C. Using the energy of ATP hydrolysis to move nucleososmes
Which of the following changes is least likely to arise from a point mutation in a regulatory region of a gene? Question 49 options: A) a mutation that changes the time in an organism's life during which a protein is expressed B) a mutation that eliminates the production of a protein in a specific cell type C) a mutation that changes the subcellular localization of a protein D) a mutation that increases the level of protein production in a cell
C. a mutation that changes the subcellular localization of a protein.
Operons ___________________________. Question 42 options: A) are commonly found in eukaryotic cells. B) are transcribed by RNA polymerase II. C) contain a cluster of genes transcribed as a single mRNA. D) can only be regulated by gene activator proteins.
C. contain a cluster of genes transcribed as a single mRNA
Which of the following statements about miRNAs is false? Question 47 options: A) One miRNA can regulate the expression of many genes. B) miRNAs are transcribed in the nucleus from genomic DNA. C) miRNAs are produced from rRNAs. D) miRNAs are made by RNA polymerase.
C. miRNAs are produced from rRNAs
The sigma subunit of bacterial RNA polymerase ___________________. Question 34 options: A) contains the catalytic activity of the polymerase. B) remains part of the polymerase throughout transcription. C) recognizes promoter sites in the DNA. D) recognizes transcription termination sites in the DNA.
C. recognizes promoter sites in the DNA
In a DNA double helix, _____________________. Question 15 options: A) the two DNA strands are identical. B) purines pair with purines. C) thymine pairs with cytosine. D) the two DNA strands run antiparallel.
D
Question 12 (1 point) Question 12 Unsaved The maximum velocity (Vmax) of an enzymatic reaction is an important piece of information regarding how the enzyme works. What series of measurements can be taken in order to infer the maximum velocity of an enzyme-catalyzed reaction? Question 12 options: A) the rate of substrate consumption after the system reaches equilibrium, for several reactant concentrations B) the rate of product consumption shortly after mixing the enzyme and substrate C) the rate of substrate consumption at high levels of enzyme concentration D) the rate of substrate consumption shortly after mixing the enzyme and substrate, for several substrate concentrations
D
Which diagram accurately represents the directionality of DNA strands at one side of a replication fork? Question 28 options: A) a B) b C) c D) d
D
In glycolysis, kinases function to ____________. Question 85 options: A) transfer phosphate groups to carbon molecules from ATP B) transfer phosphate groups from carbon molecules to ADP C) Oxidize carbon molecules D) Both A and B during different stages of glycolysis
D) Both A and B during different stages of glycolysis
Carbon fixation is used to bring carbon derived from ___________ molecules into metabolism. Question 94 options: A) Acetly CoA B) CH4 C) Pyruvate D) CO2
D) CO2
Protein E can bind to two different proteins, S and I. The binding reactions are described by the following equations and values: E + S -> ES Keq for ES = 10 E + I -> EI Keq for EI = 2 Given the equilibrium constant values, which one of the following statements is true? Question 11 options: A) E binds I more tightly than S. B) When S is present in excess, no I molecules will bind to E. C) The binding energy of the ES interaction is greater than that of the EI interaction. D) Changing an amino acid on the binding surface of I from a basic amino acid to an acidic one will probably make the free energy of association with E more negative. Save
D) Changing an amino acid on the binding surface of I from a basic amino acid to an acidic one will probably make the free energy of association with E more negative.
PCR involves a heating step, followed by a cooling step, and then DNA synthesis. What is the primary reason for why this cooling step is necessary? Question 62 options: A) Cooling the reaction ensures the integrity of the covalent bonds holding the nucleotides together in the DNA strand. B) Cooling the reaction gives the DNA polymerase an opportunity to rest from the previous cycle so that it will be ready for the next round of synthesis. C) Transcription takes place during the cooling step. D) Cooling the reaction brings the temperature down to a level that is compatible with the short primers forming stable hydrogen bonds with the DNA to be amplified. Save
D) Cooling the reaction brings the temperature down to a level that is compatible with the short primers forming stable hydrogen bonds with the DNA to be amplified.
DNA ligase is an enzyme used when making recombinant DNA molecules in the lab. In what normal cellular process is DNA ligase involved? Question 58 options: A) none, it is only found in virally infected cells B) transcription C) transformation D) DNA replication
D) DNA replication
Which is not part of the unfolded protein response (UPR)? Question 97 options: A) Increase the size of the ER B) Decrease in protein synthesis C) Increase in chaperone production D) Decrease cell size
D) Decrease cell size
___________ are cell-cell junctions that indirectly connect intermediate filament networks between cells. Question 116 options: A) Tight Junctions B) Centrosomes C) Synaptic clefts D) Desmosomes
D) Desmosomes
During mitosis, centrosomes (spindle poles), send out many microtubules. Which of the following is NOT a function performed by microtubules originating from a spindle pole during mitosis: Question 119 options: A) Attach to chromosomes at kinetochores and pull apart sister chromatids. B) Attach to a microtubule from the other spindle pole and push the spindle poles apart. C) Attach to the cell cortex and pull the spindle pole towards the cortex. D) Form the contractile ring and pinch apart the two daughter cells during cytokinesis.
D) Form the contractile ring and pinch apart the two daughter cells during cytokinesis.
You have a test tube containing empty tubulin dimers (alpha and beta subunits). Which molecule would you add to the test tube to encourage microtubule synthesis? Question 115 options: A) ADP B) ATP C) GDP D) GTP
D) GTP
Nuclear transport is power by _____________. Question 100 options: A) Voltage gated ion channels B) Electron transport C) Proton motive force D) GTP hydrolysis
D) GTP hydrolysis
Which of the following is true of a retrovirus but not of the Alu retrotransposon? Question 53 options: A) It requires cellular enzymes to make copies. B) It can be inserted into the genome. C) It can be excised and moved to a new location in the genome. D) It encodes its own reverse transcriptase.
D) It encodes its own reverse transcriptase.
Which of the following statements does not accurately describe the events involved in the propagation of an action potential? Question 80 options: A) An initial influx of Na+ through a small cluster of channels causes local depolarization of the membrane. B) Local depolarization causes nearby Na+ channels to open. C) Channels in depolarized regions of the membrane are inactivated until the resting membrane potential is reestablished. D) The opening of transmitter-gated K+ channels helps to repolarize the membrane.
D) The opening of transmitter-gated K+ channels helps to repolarize the membrane.
K+ leak channels are found in the plasma membrane. These channels open and close in an unregulated, random fashion. What do they accomplish in a resting cell? Question 79 options: A) They set the K+ concentration gradient to zero. B) They set the membrane potential to zero. C) They transport K+ and Na+ ions D) They keep the electrochemical gradient for K+ at zero.
D) They keep the electrochemical gradient for K+ at zero.
Energy in the form fats are stored as ___________ molecules. Question 83 options: A) Phospholipid B) Cholesterol C) Glycogen D) Triacylglycerol
D) Triacylglycerol
You want to design a DNA probe used for hybridization to isolate a clone from a cDNA library. Which of the following concerns about DNA probe design is the most legitimate? Question 60 options: A) You must be careful when designing your probe to take into account which DNA strand was transcribed in mRNA and choose a probe complementary to the mRNA. B) You must be careful not to include any DNA sequences in your probe that are upstream (5′) of the AUG start codon. C) You must make sure that all the DNA sequences in your probe lie within an exon, and do not span two exons. D) You must make sure that all the DNA sequences in your probe are not located downstream (3′) of the polyadenylation signal.
D) You must make sure that all the DNA sequences in your probe are not located downstream (3′) of the polyadenylation signal.
Diversity among the oligosaccharide chains found in the carbohydrate coating of the cell surface can be achieved in which of the following ways? Question 72 options: A) varying the types of sugar monomers used B) varying the types of linkages between sugars C) varying the number of branches in the chain D) all of the above Save
D) all of the above
Which of the following membrane lipids does not contain a fatty acid tail? Question 67 options: A) phosphatidylcholine B) a glycolipid C) phosphatidylserine D) cholesterol
D) cholesterol
The stimulation of auditory nerves depends on the opening and closing of channels in the auditory hair cells. Which type of gating mechanism do these cells use? Question 77 options: A) voltage-gated B) extracellular ligand-gated C) intracellular ligand-gated D) mechanically gated
D) mechanically gated
Which of the following is required for the secretion of neurotransmitters in response to an action potential? Question 81 options: A) neurotransmitter receptors B) Na+-K+ pumps C) voltage-gated K+ channels D) voltage-gated Ca2+ channels Save
D) voltage-gated Ca2+ channels
Hershey and Chase used radiolabeled macromolecules to identify the material that contains heritable information. What radioactive material was used to track DNA during this experiment? Question 17 options: 3H 14C 35S 32P
D. 32P
Choose the answer that best fits the following statement: Cholesterol is an essential component of biological membranes. Although it is much smaller than the typical phospholipids and glycolipids in the membrane, it is a(n) _________________ molecule, having both hydrophilic and hydrophobic regions. Question 7 options: A) polar B) oxygen-containing C) hydrophobic D) amphipathic
D. Amphipathic
The energy used by the cell to generate specific biological molecules and highly ordered structures is stored in the form of _____________. Question 8 options: A) Brownian motion B) heat C) light waves D) chemical bonds
D. Chemical Bonds
The pH of an aqueous solution is an indication of the concentration of available protons. However, you should not expect to find lone protons in solution; rather, the proton is added to a water molecule to form a(n) ______________ ion. Question 5 options: A) hydroxide B) ammonium C) chloride D) hydronium
D. Hydronium
Which of the following functions do you not expect to find in the set of genes found in all organisms on Earth? Question 51 options: A) DNA replication B) DNA repair C) protein production D) RNA splicing Save
D. RNA splicing
Similar to proteins and PAGE, DNA molecules may be sorted through electrophoresis. This is because _____________. This results in ___________, similar to protein gel electrophoresis. Question 24 options: DNA is polar and soluble in water / larger DNA molecules migrating further through the gel DNA is has many hydrogen bonds / larger DNA molecules migrating further through the gel The sugar-phosphate backbone gives DNA a charge / larger DNA molecules migrating further through the gel The sugar-phosphate backbone gives DNA a charge / smaller DNA molecules migrating further through the gel
D. The sugar-phosphate backbone gives DNA a charge/ smaller DNA molecules migrating further through the gel.
Which of the following statements about mobile genetic elements is true? Question 52 options: A) Mobile genetic elements can sometimes rearrange the DNA sequences of the genome in which they are embedded by accidentally excising neighboring chromosomal regions and reinserting these sequences into different places within the genome. B) DNA-only transposons do not code for proteins but instead rely on transposases found in cells that are infected by viruses. C) The two major families of transposable sequences found in the human genome are DNA-only transposons that move by replicative transposition. D) During cut-and-paste transposition, the donor DNA will no longer have the mobile genetic element embedded in its sequence when transposition is complete.
D. during cut-and-paste transposition, the donor DNA will no longer have the mobile genetic element embedded in its sequence when transposition is complete.
Which of the following would contribute most to successful exon shuffling? Question 50 options: A) shorter introns B) a haploid genome C) exons that code for more than one protein domain D) introns that contain regions of similarity to one another
D. introns that contain regions of similarity to one another.
Which of the following is not a general mechanism that cells use to maintain stable patterns of gene expression as cells divide? Question 46 options: A) a positive feedback loop, mediated by a transcriptional regulator that activates transcription of its own gene in addition to other cell-type-specific genes B) faithful propagation of condensed chromatin structures as cells divide C) inheritance of DNA methylation patterns when cells divide D) proper segregation of housekeeping proteins when cells divide
D. proper segregation of housekeeping proteins when cells divide.
A mutant cell is no longer able to produce GTP. However, you supply the cell with a GTP analogue that is similar to GTP in all ways EXCEPT that the GTP cannot be hydrolized to GDP. Which of the following is most likely to occur? Question 107 options: G-protein coupled receptors will be unable to activate G-proteins G-proteins will be permanently inactive G-proteins will be constitutively active GEF proteins will be unable to function
G-proteins will be constitutively active
Double covalent bonds are both shorter and stronger than single covalent bonds, but they also limit the geometry of the molecule because they ____________________. Question 4 options: limit the rotation of the bonded atoms create a new arrangement of electron shells change the reactivity of the bonded atoms prevent addtional bonds from being formed with the bonded atoms.
Limit the rotation of bonded atoms
The cytoskeleton provides support, structure, motility, and organization, and it forms tracks to direct organelle and vesicle transport. Which of the cytoskeletal elements listed below is the thickest? Question 3 options: actin filaments microtubules intermediate filaments none of the above (they are all of equal thickness)
Microtubules
Which of the following is generally true for activated G-proteins? Question 108 options: They have GTP bound in their beta subunit. They are bound to their GPCR The trimer is dissociated into two parts: a solitary gamma subunit and an alpha/beta dimer The lifetime of their activity is dictated by the G-protein's own intrinsic GTPase activity
The lifetime of their activity is dictated by the G-protein's own intrinsic GTPase activity
With fully automated Sanger sequencing, all four chain-terminating ddNTPs can be added into a single reaction. This is different from the traditional slab gel Sanger sequencing, where a different reaction had to be carried out for each ddNTP. The mixing of all four ddNTPs can be carried out because ______________. Question 64 options: A) the fully automated Sanger sequencing reactions are loaded onto a capillary gel. B) the fully automated Sanger sequencing reactions utilize ddNTPs each labeled with a different fluorescent tag, which allows all four ddNTPs to be incorporated into a single molecule of DNA. C) the fully automated Sanger sequencing reactions generate a set of products, each of which carries a single fluorescent tag whose color reveals the identity of the base that is at the end of the product. D) the fully automated Sanger sequencing reactions do not require DNA polymerase because the bases are read as the DNA is pulled through a tiny pore at the end of the capillary gel.
vC) the fully automated Sanger sequencing reactions generate a set of products, each of which carries a single fluorescent tag whose color reveals the identity of the base that is at the end of the product.
