BIO Exam 4 Practice Test 174 Questions with Verified Answers,100% CORRECT

BIO Exam 4 Practice Test 174 Questions with Verified Answers The term polycistronic mRNA means: A.There is more than one mRNA strand produced during each round of transcription. B.There are multiple promotors to initiate transcription of this RNA. C.There are multiple operators for transcription of this RNA. D. There are multiple open reading frames in the mRNA produced. - CORRECT ANSWER D Please choose the true statement: A. During replication, the DNA leading strand is polymerized in the 5' to 3' direction, but the lagging strand is polymerized in the 3' to 5' direction B. During replication, both the leading and lagging DNA templates are read in the 3' to 5' direction. C. During replication, both the leading and lagging strands of DNA are polymerized in the 3' to 5' direction. D. Both a and b are true. - CORRECT ANSWER B In prokaryotes like E. coli, what does the term consensus sequence refer to? A. It is a DNA sequence that is part of the origin of replication. B. It is a DNA sequence that represents the optimal promoter for transcription. C. It is an RNA sequence that represents the ribosome binding site for the initiation of translation. D. It is an RNA sequence that represents the most common transcription termination site - CORRECT ANSWER B Which of the following contributes to regulation of the lac operon? a. cAMP b. allolactose c. the catabolite activated proteind. All of these contribute to lac operon regulation. - CORRECT ANSWER B Please choose the true statement: A. Replication uses a DNA template in the synthesis of DNA. B.Replication uses an DNA template in the synthesis of RNA. C.Transcription uses an RNA template in the synthesis of RNA. D. Translation uses a DNA template in the synthesis of RNA. - CORRECT ANSWER A If bacteria containing the lac operon were grown in low glucose and high lactose, which of the following would be true? A. The lac operon would be repressed by the lac repressor. B. The lac operon would not be repressed, but also would not be activated; it would be transcribed at basal levels. C. The lac operon would be activated. D. The lac operon would be repressed by the catabolite activated protein. - CORRECT ANSWER C Please choose the true statement: A. PKU (phenylketonuria) results from a defect in the synthesis of phenylalanine. B. Gout results from a defect in the salvage pathway of purines. C. Huntingdon's disease results from a defect in the purine salvage pathway. D. Lesch-Nyhan syndrome results from a defect in the purine salvage pathway. - CORRECT ANSWER B/D How is pepsinogen activated? A. It is activated by trypsin through proteolytic cleavage. B. It is activated by enteropeptidase through proteolytic cleavage. C. It is activated by low pH which causes auto-proteolytic cleavage. D. It is activated by high pH which causes auto-proteolytic cleavage. - CORRECT ANSWER C Muscles: Can use branched chain amino acids for fuel, but do not have urea cycle to process the ammonium that is released. True False - CORRECT ANSWER TRUE How is trypsinogen activated? A. It is activated by pepsin through proteolytic cleavage. B. It is activated by enteropeptidase through proteolytic cleavage. C. It is activated by low pH which causes auto-proteolytic cleavage. D. It is activated by high pH which causes auto-proteolytic cleavage. - CORRECT ANSWER B Please choose the true statement: A. The pyrimidines found in nucleic acid are guanine, uracil, and cytosine. B. The pyrimidines found in nucleic acid are uracil, thymine, and cytosine. C. The purines found in nucleic acid are guanine and cytosine. D. The purines found in nucleic acid are glycine and alanine. - CORRECT ANSWER B The next 2 questions use Figure 1, which represents protease active sites. 12. Which of the proteases would cleave after arginine? A. enzyme 1 B. enzyme 2 C. enzyme 3 - CORRECT ANSWER B 13. Which of these proteases would cleave after tryptophan? A. enzyme 1 B. enzyme 2 C. enzyme 3 - CORRECT ANSWER A Please choose correct parings of enzyme and product: A. RNA Pol I: mRNA, RNA Pol II: rRNA, RNA Pol III: tRNA. B. RNA Pol I: tRNA, RNA Pol II: mRNA, RNA Pol III: tRNA. C. RNA Pol I: rRNA, RNA Pol II: tRNA, RNA Pol III: mRNA. D. RNA Pol I: tRNA, RNA Pol II: rRNA, RNA Pol III: mRNA. E. There are no correct statements. - CORRECT ANSWER E Which of the following intermediates can be used to make glucose in humans? a. Alanine b. Lysine c. Leucine d. All the above can do this. - CORRECT ANSWER A Which enzyme polymerizes the primer during replication in prokaryotes? A. Polα B. Polδ C. PolI D. Pol III E. DnaA F. DnaG - CORRECT ANSWER F A point mutation that changes CAC to CAT represents A. a transition mutation. B. a silent mutation. C. a nonsense mutation. D. Both a and b are true. E. Both a and c are true. - CORRECT ANSWER D Which of the following is True? a. During the de novo synthesis of purines bases are formed first, then are attached to PRPP. b. The immediate products of HGPRT are either thymine monophosphate, or hypoxanthine monophosphate, and pyrophosphate. c. The synthesis of RNA and DNA is driven forward by pyrophosphate release and subsequent hydrolysis. d. All of the above are true - CORRECT ANSWER C What amino acid has an R-group that you might expect to go from a non-protonated to protonated state following a shift from pH 7.3 (intracellular) to ~ pH 2 after being secreted into the lumen of the stomach? a. Lysine b. Glutamine c. Aspartate d. Alanine e. Tyrosine - CORRECT ANSWER C Which of the following intermediates can be used to make glucose in humans? a. Alanine b. Lysine c. Leucine d. All the above can do this. - CORRECT ANSWER A Which intermediate is formed during urea synthesis? A. Succinyl CoA B. Carbamoyl phosphate c. Succinate d. Aspartate - CORRECT ANSWER B Please select the true statement: A. Alanine transaminase uses alanine and alpha-ketoglutarate to form malate and glutamate. B. Loss of homogentisate oxygenase activity, can lead to alkaptonuria, which causes excretion of homogentisate in the urine. C. In urea synthesis, one amino group comes from ammonia, another amino group comes from aspartate, and the carbon comes from fumarate. D. The kidneys are the major site of urea production via the urea cycle. - CORRECT ANSWER B Please choose the true statement: A. The basal transcription factors in E. coli that are present at the initiation site of Pol II transcripts are: TFIIA, TFIIB, TFIID, TFIIE, TFIIF, and TFIIH. B. TFIID has the helicase and kinase activity necessary for promoter escape. C. The UP sequence is a bacterial DNA sequence found upstream of transcripts that are used Frequently. D. Only b and c are true. E. There are no true statements here - CORRECT ANSWER C Trans factors are proteins involved in the regulation of transcription, whereas cis factors are DNA sequences involved in the regulation of transcription. True False - CORRECT ANSWER T Each bacterial genome has one chromosome with one origin of replication, while each eukaryotic genome has many chromosomes, each of which has more than one origin of replication per chromosome. True False - CORRECT ANSWER T Please choose the true statement: (Note: inosinate is the same as inosine monophosphate, and IMP) A. Inosine monophosphate is a nucleoside monophosphate with hypoxanthine for its base. B. Inosine monophosphate is an intermediate in the de novo synthesis of purines. C. In the synthesis of adenosine monophosphate, ATP is used as a phosphate source. D. All the above are true E. Only a and b are true F. None of these statements is true - CORRECT ANSWER E Please choose the *FALSE* statement: A. The conformation of A-DNA is a left-handed helix that is generated by runs of alternating purines and pyrimidines. B. The conformation of B-DNA is a right-handed helix and is the most common DNA conformation. C. U1, U2, U4, U5 and U6 snRNPs are comprised of protein and RNA and are components of the splicing machinery. D. Prokaryotes do not put a 5' guanylate cap on their mRNAs. - CORRECT ANSWER A Which of the following occurs during translation in prokaryotes like E. coli? A. EF-Tu escorts charged tRNAs to the Ribosome/mRNA complex B. IF2 Brings initiating formylated methionine (fMet) to the initiation complex. C. The major role of IF1 and IF3 is to prevent the binding of the large ribosomal subunit to the small ribosomal subunit before the initiation complex is ready. D. All the above are true. E. Only a and c are true - CORRECT ANSWER D In the de novo synthesis of pyrimidines, orotate is formed before uridylate (UMP). True False - CORRECT ANSWER T In eukaryotes, catabolism of cellular proteins occurs in lysosomes and proteasomes. True False - CORRECT ANSWER T Please choose the true statement regarding Phenylketonuria: A. This condition prevents conversion of tyrosine to phenylalanine. B. This condition is caused by a deficiency in phenylalanine hydroxylase or, more rarely, a deficiency of the cofactor tetrahydrobiopterin. C. This condition is a result of a defect in tyrosine catabolism. D. Only b and c are true. - CORRECT ANSWER B/D Which of the following is not an essential amino acid? A.Histidine B Leucine C Valine D Aspartate E These are all essential - CORRECT ANSWER D Which intermediate is a metabolite that is correctly paired with its possible fate. A Phenylalanine: Both Glucose and Ketone bodies B Tryptophan: Glucose but NOT ketone bodies C Isoleucine: Ketone bodies but NOT glucose D Leucine: Both Glucose and Ketone bodies - CORRECT ANSWER A Histone acetyl transferases increase accessibility of the DNA to transcriptional machinery by adding acetyl groups to lysines found in histone tails. True False - CORRECT ANSWER T Which of the following could be bound to DNA to initiate transcription in prokaryotes: a. Lac repressor b. TFIID c. sigma factor d. RecA - CORRECT ANSWER C Please choose the true statement regarding pyridoxal phosphate: A This cofactor contains a reactive aldehyde. B This cofactor makes a protonated Shiff base with amino groups. C This cofactor is present and necessary in all aminotransferases. D All the above are true E Only b and c are true - CORRECT ANSWER D During replication, polymerization from the leading strand template is continuous, while polymerization from the lagging strand occurs in short 5'>3' fragments called Okazaki fragments. True False - CORRECT ANSWER T The telomerase enzyme itself contains a DNA template and reverse transcriptase activity to lengthen telomeres. True False - CORRECT ANSWER F Please choose the *FALSE* statement: A The core RNA polymerase in E. coli includes two α subunits, β, β', and ω. B Cdc6, Ctd1, and Mcm2-7 are eukaryotic licensing factors. C Deamination of thymine yields uracil. D The RNA polymerase holoenzyme includes the core polymerase and the sigma factor - CORRECT ANSWER C Fatty acid synthesis - CORRECT ANSWER Acetyl CoA Carboxylase Glycolysis - CORRECT ANSWER PFK1 Gluconeogenesis - CORRECT ANSWER Glucose 6-phosphatase Oxidative pentose phosphate pathway - CORRECT ANSWER Glucose 6-phosphate dehydrogenase Select the *FALSE *statement: A The major site for glycogen storage in the body - as determined by concentration of glycogen in individual cells - is the liver. B The major tissue for glycogen storage in the body - as determined by the amount of cells containing glycogen in that tissue - is skeletal muscle tissue. C. The main source of glucose release, for the maintenance of glucose levels in the blood, is muscle tissue. D The liver and kidneys can release free glucose because these tissues have the enzyme glucose 6-phosphatase. - CORRECT ANSWER C Sulfonamides are a class of antibiotic that inhibits translation in bacteria by preventing the formation of the initiation complex. True False - CORRECT ANSWER F Please choose the true statement: a. During replication, the DNA leading strand is polymerized in the 5' to 3' direction, but the lagging strand is polymerized in the 3' to 5' direction b. During replication, the DNA template is read in the 3' to 5' direction. c. During replication, both strands of DNA are polymerized in the 3' to 5' direction. d. Both b and c are true. e. None of these statements is true. - CORRECT ANSWER B Please choose the true statement: a. PKU (phenylketonuria) results from a defect in the de novo synthesis of pyrimidines. b. Severe combined immunodeficiency results from a defect in tyrosine catabolism. c. Gout can result from a defect in the salvage pathway of purines. d. Huntingdon's disease results from a defect in the salvage pathway of purines e. Both b and c are true. f. None of these statements is true - CORRECT ANSWER C Please choose the true statement: a. The pyrimidines found in nucleic acid are guanine, uracil, and cytosine. b. The pyrimidines found in nucleic acid are uracil, thymine, and cytosine. c. The purines found in nucleic acid are guanine and cytosine. d. The purines found in nucleic acid are glycine and alanine. - CORRECT ANSWER B Please choose correct parings of enzyme and primary product: a. RNA Pol I: mRNA, RNA Pol II: rRNA, RNA Pol III: tRNA. b. RNA Pol I: rRNA, RNA Pol II: tRNA, RNA Pol III: mRNA. c. RNA Pol I: rRNA, RNA Pol II: mRNA, RNA Pol III: tRNA. d. RNA Pol I: tRNA, RNA Pol II: mRNA, RNA Pol III: rRNA. e. There are no correct statements - CORRECT ANSWER C Which enzyme polymerizes the primer during replication in eukaryotes? a. Pol α b. Pol δ c. Pol I d. Pol III e. Sigma factor - CORRECT ANSWER A Which of the following intermediates can be used to make glucose in humans? a. Alanine b. Lysine c. Leucine d. All the above are glucogenic amino acids. - CORRECT ANSWER A The CAC to CGC mutation is a point mutation called a transition mutation. True False - CORRECT ANSWER T Please select the true statement: a. The mRNA template is read in the 3' - 5'direction during translation. b. In bacteria and eukaryotes, mRNA is synthesized in the 3' - 5'direction. c. The DNA template is read in the 3' - 5' direction during transcription. d. All the above are true. e. There are no true answers here. - CORRECT ANSWER C Lesch-Nhyan syndrome is a fatal disease caused by an inability to break down branched chain amino acids. True False - CORRECT ANSWER F Which intermediate is formed from the breakdown of argininosuccinate in the urea cycle, and links the urea cycle with the TCA cycle? a. Succinyl CoA b. Malate c. Fumarate d. Succinate - CORRECT ANSWER C Please select the true statement: a. In the purine salvage pathway, the enzyme HGPRT transfers hypoxanthine and cytosine to PRPP. b. Alcaptonuria is caused by overabundance of homogentisate, which is released in the urine. c. The transamination of alanine, with alpha-ketoglutarate as an acceptor alpha-ketoacid, yields pyruvate and glutamate. d. All the above are true. e. Only b and c are true. - CORRECT ANSWER E Please choose the true statement: a. The basal transcription factors in E. coli that are present at the initiation site of Pol II transcripts are: TFIIA, TFIIB, TFIID, TFIIE, TFIIF, and TFIIH. b. TFIID has the helicase and kinase activity necessary for promoter escape. c. The UP sequence is a bacterial DNA sequence found upstream of transcripts that are used frequently. d. Only b and c are true. e. There are no true statements here - CORRECT ANSWER C Please choose the true statement: (Note: inosinate is the same as inosine monophosphate, and IMP) a. Inosine monophosphate is a nucleoside monophosphate with hypoxanthine for its base. b. Inosine monophosphate is an intermediate in the de novo synthesis of purines. c. In the synthesis of adenosine monophosphate, ATP is used as a phosphate source. d. All the above are true e. Only a and b are true f. None of these statements is true. - CORRECT ANSWER E Please choose the *FALSE* statement: a. The conformation of Z-DNA is a left-handed helix and is generated largely by runs of alternating purines and pyrimidines. b. The conformation of B-DNA is a right-handed helix and is the most common DNA conformation. c. U1, U2, U4, U5 and U6 snRNPs are comprised of protein and RNA and are components of the splicing machinery. d. 5S RNA is a component of DNA polymerase alpha and is used for sequence recognition. - CORRECT ANSWER D Please choose the true statement regarding Phenylketonuria: a. This condition is caused by an overabundance of active phenylalanine hydroxylase. b. This condition may be caused by a deficiency in the cofactor pyridoxal phosphate c. This condition is a result of a defect in phenylalanine catabolism. d. Only b and c are true. - CORRECT ANSWER C During the de novo synthesis of purines, bases are formed first, then are attached to PRPP. True False - CORRECT ANSWER F In mammalian systems, nitrogen is fixed by the enzyme nitrogenase. True False - CORRECT ANSWER F Gluconeogenesis - CORRECT ANSWER F. Fructose 1,6 bisphosphatase Glycolysis: - CORRECT ANSWER Hexokinase Fatty acid degradation - CORRECT ANSWER Carnitine acyltransferase I Fatty acid synthesis - CORRECT ANSWER D Select the*FALSE* statement: a. Pyrimidines are synthesized by de novo synthesis and by the pyrimidine salvage pathway. b. Enteropeptidase is a protease that cleaves tripsinogen to form the active trypsin. c. Photolyase resolves thymine dimers in prokaryotes like E. coli, and eukaryotes like humans. d. In the purine salvage pathway, HGPRT transfers a salvaged purine base to a PRPP platform. - CORRECT ANSWER C Please choose the true statement: a. Cdc6, Ctd1, and Mcm2-7 are eukaryotic licensing factors. b. Deamination of the base, thymine, yields uracil. c. DNA is more resistant to hydrolytic damage than RNA because DNA is reduced at the 2' position whereas RNA is not. d. all the above are true. e. only a and c are true. - CORRECT ANSWER E The telomerase enzyme contains an RNA template and Pol α activity to lengthen telomeres. True False - CORRECT ANSWER F Which of the following is true regarding the urea cycle? a. The synthesis of carbamoyl phosphate requires two molecules of ATP. b. Aspartate is used as one source of nitrogen, and bicarbonate is the carbon source. c. This pathway utilizes both cytoplasmic and mitochondrial enzymes. d. All the above are true. e. Only b and c are true. f. None of these statements is true. - CORRECT ANSWER D The urea cycle is highly active in muscles when proteins are catabolized for energy. True False - CORRECT ANSWER F The addition of amino acids to an mRNA template is directed by the amino acid loaded onto the tRNA and the template mRNA codon. True False - CORRECT ANSWER F . Please select the true statement: a. The core RNA polymerase in E. coli includes αI and II, β, β', ω. b. The active site in E. coli RNA polymerase is in the α subunits. c. The RNA polymerase holoenzyme includes the core polymerase and the sigma factor. d. All the above are true. e. Only a and c are true. f. Only b and c are true. - CORRECT ANSWER E Please select the FALSE statement: a. Urate is produced during nucleotide catabolism, and is eliminated in the urine. b. Excess urate in the blood can precipitate into the kidneys and joints resulting in gout. c. Humans and other primates eliminate nitrogenous waste as allantoin. d. Urate is a potent antioxidant. - CORRECT ANSWER C Persons with PKU must reduce their intake of tyrosine throughout their life compared to persons without PKU. True False - CORRECT ANSWER F The promoter consensus sequence is a stretch of DNA in eukaryotic genes that includes the -35 and -10 regions. True False - CORRECT ANSWER F Which of the following is NOT one of the 7 majormetabolic intermediates formed during amino acid catabolism? a. Pyruvate b. Alpha-ketoglutarate c. Succinyl CoA d. Palmitate e. Acetyl CoA - CORRECT ANSWER D What amino acid is produced when the alpha-ketoacid pyruvate is transaminated? a. Alanine b. Aspartate c. Glutamate d. Glutamine - CORRECT ANSWER A Which of the following is true? a. Gout is caused by a decrease in urate production. b. Urate is a product of amino acid catabolism. c. Urate is a potent antioxidant. d. None of the above is true. - CORRECT ANSWER C This enzyme removes the RNA primer in the prokaryote, E. coli. - CORRECT ANSWER DNA Pol I This enzyme synthesizes the RNA primer in the prokaryote, E. coli - CORRECT ANSWER DnaG This enzyme is a helicase during DNA synthesis in the prokaryote, E. coli. - CORRECT ANSWER DnaB This enzyme synthesizes the RNA primer during replication in eukaryotes. - CORRECT ANSWER DNA Pol α This enzyme separates the DNA strands at the ori in E. coli. - CORRECT ANSWER DnaA This enzyme brings the RNA polymerase to the start site of transcription E. coli. - CORRECT ANSWER Sigma factor This is the enzyme that synthesizes the leading strand in human replication - CORRECT ANSWER DNA Pol ε This eukaryotic licensing factor is a helicase. - CORRECT ANSWER MCM 2-7 Please choose the true statement: a. Inosine monophosphate, IMP, is an intermediate in the de novo synthesis of pyrimidines. b. During nitrogen fixation in humans, nitrogen is split and reduced in a process that uses ATP and forms ammonium. c. Orotate is an intermediate in the synthesis of thymidylate d. ATP is the prime phosphoryl source in the synthesis of AMP. - CORRECT ANSWER C Please choose the true statement regarding phenylketonuria: a. This condition is generally caused by a deficiency in folic acid. b. The most common cause for this condition is a deficit in phenylalanine hydroxylase. c. The most common cause for this condition is a deficit in carbamoyl phosphate synthetase II d. This is caused by a defect in phenylalanine synthesis. - CORRECT ANSWER B Please choose the true statement: a. Sigma is the basal transcription factor present at the initiation site to promote transcription of pol II transcripts in eukaryotes. b. TFIIB has the helicase and kinase activity necessary for promoter escape. c. The UP sequence is found upstream of eukaryotic transcripts that are not used frequently. d. TFIID contains the Tata-binding protein, TBP. - CORRECT ANSWER D Please choose the *FALSE* statement: a. Deamination of the base, cytosine, yields uracil. b. DNA is more resistant to hydrolytic damage than RNA because DNA is reduced at the 2' position whereas RNA is not. c. A TTG to CTG mutation is a silent mutation as both encode the same amino acid. d. Homeodomain proteins are transcription factors found in prokaryotes. - CORRECT ANSWER D Please select the true statement: a. In eukaryotes, the signal sequence recruits the signal recognition particle, which helps to target this mRNA and its ribosome to the endoplasmic reticulum for protein synthesis. b. IF1, IF2 and IF3 are elongation factors that continue RNA polymerization in eukaryotes. c. If you change the amino acid that is loaded on a tRNA, the tRNA will recognize the new amino acid and bind to the codon that corresponds to that new amino acid. d. There are no true statements here. - CORRECT ANSWER A Please select the true statement: a. Glutamine synthetase in neural tissue adds an amino group to glutamate, thereby reducing levels of glutamate and ammonium in the tissues. b. The urea cycle begins in the mitochondrion but some reactions of the cycle occur in the cytosol. c. The formation of urea uses amino groups from ammonium and aspartate. d. All of the above are true. - CORRECT ANSWER D Please select the true statement: a. The proteasome is an enzyme complex on the face of enterocytes with the primary purpose of degrading proteins of dietary origin. b. The urea cycle in the muscles forms urea when muscle proteins are degraded for energy. c. The alanine cycle uses pyruvate as an alpha-ketoacid co-substrate for transamination. d. Only b and c are true. - CORRECT ANSWER C Please select the true statement: a. Deficiency in homgentisate oxidase can lead to a condition called gout. b. Deficiency in branched chain catabolic pathway can lead to alkaptonuria. c. Aflatoxin becomes more toxic through the action of the enzyme p450, which forms a highly reactive epoxide, and when this planar molecule intercalates into DNA it can cause mutations. d. Lesch-Nyhan syndrome is caused by a deficiency in glutamine synthetase. - CORRECT ANSWER C When glucose levels are low, which of the following enzymes will be activated? - CORRECT ANSWER 3. Pyruvate carboxylase 4. Glycogen phosphorylase 5. Carnitine acyl transferase I During metaphase I of meiosis, what appears to hold homologues together as a bivalent? - CORRECT ANSWER chiasmata For replication of the lagging strand, DNA is constructed in small segments called ____ that are rapidly linked to longer peices of DNA synthesized earlier. - CORRECT ANSWER Okazaki Fragments From What materials are new cell walls of two daughter plant cells derived - CORRECT ANSWER secretory products withing the Golgi-derived vesicles that form the cell plate How does meiosis raise the genetic variability in a population of organisms from one generation to the next? A. Independent assortment allows maternal and paternal chromosomes to be shuffled as gametes form. b. Genetic mutations caused by deletions. c. It changes the number of chromosomes in the organisms from generation to generation d. genetic recombination allows maternal and paternal alleles on a given chromosome to be shuffled - CORRECT ANSWER a + d a. independent assortment allows maternal and parental chromosomes to be shuffled as gametes d. genetic recombination allows maternal and parental alleles on a given chromosome to be shuffled How many types of histones are in the nucleosome core particle? - CORRECT ANSWER 4 If a DNA molecule is replicated once to produce two daughter DNA molecules. According to the semiconservative replication mechanism, which of the following is a correct description about the two daughter DNA molecules? - CORRECT ANSWER One strand of each daugher DNA is newly synthesized, the other strand of each daughter DNA molecule is from the parental DNA. the two strands from the parental DNA are complementary to each other. If the DNA content of a mother cell is 24C, after meiosis I , the DNA content of each daughter cell will be _______. - CORRECT ANSWER 24C If you fuse a G1 cell to a cel in the M phase, which of the following responses will occur? - CORRECT ANSWER The G1 nucleus will undergo premature chromosomal condensation to form a set of compacted chromosomes. In meiosis, during which process do the paired homologous chromosomes separate? - CORRECT ANSWER anaphase 1 In meiosis, genetic recombination is completed by the end of ________. - CORRECT ANSWER Pachytene In mitosis, if a chromosome fails to become aligned properly at the metaphase, which mechanism will delay the onset of anaphase? - CORRECT ANSWER spindle checkpoint The assembly of the beta-clamp around the DNA requires a multisubunit ____ that is also part of the ____; part of this structure opens the ____ so that it can fit around the DNA and then function to recruit the core polymerase. - CORRECT ANSWER clamp loader, DNA polymerase III holoenzyme, Beta clamp Nuclear localization sequence (NLS) enables a protein to pass through the nuclear pores and enter the nucleus. The classical NLSs consist of one or two short stretches of ____. - CORRECT ANSWER positively charged amino acids Once the interconnected Holliday junctions are formed, the structure must be resolved and restored to two discrete DNA molecules through another round of DNA cleavage. Which of the following statements describes a possible product of the resolutions? a. the two DNA molecules contain only short stretches of genetic exchange. b. Part one DNA molecule is covalently joined to part of the homologous DNA molecule, creating a site of genetic recombination. c. No effective crossover is created d. A crossover is created - CORRECT ANSWER A+B+C+D Cell cycle MPF (maturation-promoting factor) contains a subunit with ____ and a ____ subunit. - CORRECT ANSWER Kinase activity, cyclin The RNA polymerase synthesizing short RNA primers for intitation Okazaki fragments is called ____. - CORRECT ANSWER primase "The end-replication problem" is solved by ____. - CORRECT ANSWER telomerase The process of protein synthesis (translation) does NOT include ____. - CORRECT ANSWER transcription In eukaryotic cells, 5s rRNA genes are transcribed by ____. - CORRECT ANSWER RNA polymerase III If you extract total RNA from a cell, which of the following constitute the majority of the total RNA? - CORRECT ANSWER rRNAs Spliceosomes are macrocolecular complexes that consist of a variety of proteins and a host of snRNAs. The snRNAs in the spliceosomes ____. - CORRECT ANSWER catalytically splice pre-mRNAs What provides the energy that drives the polymerization of RNA from a DNA template? - CORRECT ANSWER ribonucleoside triphosphates (NTPs) What is the name of the site where RNA polymerase binds to the DNA prior to the beginning of transcription? - CORRECT ANSWER Promoter What is the name of the proteins that make up the nuclear lamina and of what structural superfamily are they a member? - CORRECT ANSWER lamins, intermediate filaments The chromosomes regions containing rDNA are located in ____. - CORRECT ANSWER nucleoli Based on the Wobble Hypothesis, the anticodon 5'IAU3' will not recognize which of the following codons? - CORRECT ANSWER 5'AUG3' If A is at the 3rd position in the codon it can base pair with U or I, if either of these is present at the 1st position in the anticodon. If U is at the 3rd position in the codon it can base pair with A, G or I, if either of these is present at the 1st position in the anticodon. If G is at the 3rd position in the codon it can base pair with C or U, if either of these is present at the 1st position in the anticodon. If C is at the 3rd position in the codon it can base pair with G or I, if either of these is present at the 1st position in the anticodon. [5] During meiosis, homologous chromosomes will associate with one another. This of chromosomes pairing is called synapsis. Synapsis occurs in ____. - CORRECT ANSWER zygotene There are three pairs of chromosomes in a specific organism. During meiosis, how many assortment combination of maternal and parental hologous chromosomes this organism could have? - CORRECT ANSWER 8 There are different types of RNAs in the cell. Which of the following RNAs carry genetic information (code)for polypeptide synthesis? - CORRECT ANSWER mRNAs Synthesis of an RNA from a DNA template is called transcription. Which of the following components are required for transcription? - CORRECT ANSWER Promoter, Transcription factors, DNA template, RNA polymerase Multiple basic elements are found in the promoter region of a gene (DNA). Minus 1 nucleotide is ____. - CORRECT ANSWER the nucleotide preceding the one at which transcription is initiated Eukaryotic cells have multiple RNA polymerases. Which of the following RNA genes is not transcribed by RNA polymerase I? - CORRECT ANSWER 5S rRNA The ____ is located about 10 bases upstream from the initiation site. It has the consensus sequence ____ and is responsible for identifying the precise nucleotide at which ____ begins. - CORRECT ANSWER Pribnow box, TATAAT, transcription Which of the following is NOT a normal property of eukaryotic mRNAs? - CORRECT ANSWER They are found in the cytoplasm and inside the Golgi complex What happens if histone H1 is selectively extracted from compacted chromatin (30nm fibers)? - CORRECT ANSWER 30-nm fibers uncoil to form a thinner more extended beaded filament If cells cannot replicate the ends of their DNA, what should happen with each round of cell division? - CORRECT ANSWER The chromosomes should get shorter. Bacteria are grown in a medium containing 15NH4Cl for a number of generations so that all of their genomes are made of fully 'heavy' DNA. The bacteria are then moved to a new medium and grown in 14NH4Cl. After one generation time,, what does the DNA look like? - CORRECT ANSWER All of the DNA is made of 1 'heavy' strand and 1 'light' strand Replication moves outward from the origin in ____ directions and is said to be ____. - CORRECT ANSWER both, bidirectional Where is DNA gyrase normally positioned supercoiled DNA into negatively supercoiled DNA in the replicating circular, bacterial chromosome? - CORRECT ANSWER it travels along the DNA ahead of the replication fork Which of the following DNA molecules serve as an effective template for DNA synthesis? 1. an intact linear, double stranded DNA 2. a single stranded, cirular DNA 3. a partially double stranded DNA 4. an intact, linear single stranded DNA - CORRECT ANSWER 3 Scientists often stain chromosomes from mitotic cells and photograph the chromosomes in the microscope. Each chromosome are matched up in homologous pairs and they are placed in order of decreasing size. these pictures can be used to screen individuals for chromosomal abnormalities, like extra, missing or grossly altered chromosomes. What is such a picture called. - CORRECT ANSWER karyotype What is responsible for joining eukaryotic Okazaki fragments together? - CORRECT ANSWER DNA ligase What binds to the ORC (origin recognition complex) to assemble the prereplication complex (pre-RC) taht is competent to initiate replication? - CORRECT ANSWER licensing factors The DNA strand growing toward the replication fork grows ____ in a 5'->3' direction as the replication for advances and is called the ____. - CORRECT ANSWER continuously, leading strand The macromolecular complex that associates with each intron and spices it is called a - CORRECT ANSWER spliceosome The greatest variability among codons that specify the same amino acid occurs ____. - CORRECT ANSWER in the third nucleotide of the triplet Which of the following is not required for protein synthesis - CORRECT ANSWER Anions Cations however are required What is always the first amino acid incorporated at the N-terminus of a nasent polypeptide chain - CORRECT ANSWER methionine The period in the cell cycle between the end of cell division and the beginning of DNA syntesis is called the ___ phase. - CORRECT ANSWER G1 When do most of the preperations for mitosis occur, including such activities as DNA replication? - CORRECT ANSWER interphase Movement past the transition point near the end of G2 that moves cells on the mitosis requires cdc2 activation by ____. - CORRECT ANSWER mitotic cyclins Cells that have a single set of chromosomes are said to have a ____ number of chromosomes; cells that contain two full sets of paired chromosomes are sid to have a ____ number of chromosomes. - CORRECT ANSWER haploid, diploid the corresponding segment of DNA from which the primary transcript is transcribed is called a ____. - CORRECT ANSWER transcription unit Which of the following binds to the TATA box? - CORRECT ANSWER TBP (TATA binding protein) The thin filamentous meshwork within the nucleus that is bound by integral membrane proteins of the inner surface of the nuclear envelope in animals cells is called the ____. - CORRECT ANSWER nuclear lamina What happens to DNA ( circular DNA or linear DNA that is not free to rotate) when it becomes underwound - CORRECT ANSWER it becomes negatiely supercoiled All the DNA polymerases lay down nucleotides in a ____ direction and move along the template in a ____ direction. - CORRECT ANSWER 5'->3', 3'->5' What proteins bind selectively to single stranded DNA and are responsible for keeping it extended and preventing it from being rewound? - CORRECT ANSWER Single-stranded DNA binding (SSB) proteins The enzyme that adds new repeat units to the ____ end of the overhanging strand of chromosomal DNA is called ____. - CORRECT ANSWER 3', telomerase The separation of the poles of the cell during anaphase is accomplished by ____. - CORRECT ANSWER the sliding of overlapping microtubules from opposite poles over one another in opposite directions What happens if chromatin is treated with nonspecific nucleases? - CORRECT ANSWER Most DNA is converted into fragments that are about 200 (or multiples of 200) base pairs long Primase is a _____ - CORRECT ANSWER distinct type of RNA polymerase several rRNAs and dozens of proteins from ribosomes. Which of the following rRNAs are found in the large subunits of ribosomes a. 28s rRNA b. 18s rRNA c. 5.8s rRNA d. 5s rRNA - CORRECT ANSWER A+B+C The end replication problem is because ____. - CORRECT ANSWER DNA polymerases do not initiate the synthesis of a strand of DNA The _____ strand fragment grows away from the replication fork toward the ____. end of the previously synthesized fragment to which it is subsequently linked. - CORRECT ANSWER lagging, 5' Nucleolus is an irregular shaped structure found in the nucleus, which contains____. a. DNA sequences encoding rRNAs b. DNA sequences encoding histones c. the nascent pre-rRNA transcripts and associated proteins d. Ribosomal subunits in various stages of assembly e. DNA sequences encoding tRNAs - CORRECT ANSWER a+c+d in eukaryotic cells, 5s rRNA is encoded by a large number of identical genes. which of the following statements about 5s RNA is not true - CORRECT ANSWER The promoters of 5s rRNA genes are in front of the coding sections of the genes Which of the following statements about cellular RNA is not true - CORRECT ANSWER mRNA and its precursor hnRNA constitute a small percentage of the RNA that is being synthesized by the cell at any given time mRNA and precursor constitute the larges precentage of synthesized RNA Chromatin has a well organized structure. when treated with nospecific nucleases, chromatin is generally digested into fragments of about _____ in length. - CORRECT ANSWER 200bp Histones are a group of proteins that posses an unusually high content of the amino acids_____. - CORRECT ANSWER arginine and lysine When chromatin is released from nuclei and prepared at physiological ionic strength, a fiber of about 30nm is observed. the DNA packing ratio of the 30nm fiber is - CORRECT ANSWER 7:1 during DNA replication, the new DNA molecules are quickly assembled into nucleosomes. Which of the following is true for histone assembly? - CORRECT ANSWER The (H2A/H2B)2(H3H4)2 octomer present prior to replication remain intact and are distributed randomly between the two daughter DNA molecules. Eukaryotes have five classic DNA polymerases. Which DNA polymerase is the primary DNA synthesizing enzyme during replication - CORRECT ANSWER Polymerase delta Which of the following is not a piece of evidence that the nucleus is and organized organelle? - CORRECT ANSWER the larger rRNA genes are clustered and exclusively transcribed in the nucleolus. Based on the wobble hypothesis, an inosine (I) at the first position of an anticodon does not pair with a ____ at the third position of the codon - CORRECT ANSWER G Genetic information is encoded in genetic codons. Which of the following descriptions about codons is true - CORRECT ANSWER Codons specify the same amino acids are clustered within a particular portion of the genetic codon chart Splicing of eukaryotic mRNAs involves a macromolecular complex spliceosome, which consists of a variety of proteins and a number of distinct ribonucleoprotein particles. The small nuclear RNAs in the spliceosome play a critical role in splicing processes, whereas the proteins play different functions. Which of the following functions is not played by the proteins of the spliceosome. - CORRECT ANSWER Catalyzing the chemical reactions of pre-mRNA splicing Ribosomes contain several rRNAs and dozens of ribosomal proteins. Which of the following descriptions about ribosome strucuture is not correct? - CORRECT ANSWER none of the others the interface between the small and large subunits froms a relatively spacious cavity that is lined almost exclusively by RNA. A tunnel runs completely through the core of the small subunit beginning at the active site. The active site, where AAs are covalently linked to one another, also consists of RNA The mRNA is situated in a narrow channel that winds around the neck of the small subunit passing through the A, P, E sites.