RNAS-C Practice Exam 1|49 Questions with Verified Answers,100% CORRECT

RNAS-C Practice Exam 1|49 Questions with Verified Answers What type of RNA specifies the amino acid sequence of a particular protein? a. miRNA b. tRNA c. mRNA d. rRNA e. Both c and d are correct answers. - CORRECT ANSWER mRNA A nucleic acid is a. a polymer of nucleotides. b. hydrophobic. c. linked to an amino acid via a peptide bond. d. a form of energy storage in the cell. e. linked to other nucleic acids by covalent bonds between bases. - CORRECT ANSWER A polymer of nucleotides If the first exon of a primary transcript encoding a nuclear protein (that is not normally alternatively splice) is incorrectly removed, what will become of that PROTEIN? a. It will not be synthesized. b. It will never leave the nucleus. c. It will be fully synthesized in the cytosol and never enter the nucleus. d. It will immediately be degraded in the lysosome. e. Both a and b are correct answers. - CORRECT ANSWER It will not be synthesized The assembly of the large and small ribosomal subunits each with their associated rRNA a. occurs on the surface of the endoplasmic reticulum. b. occurs in the nucleus. c. occurs in the cytosol, not in association with the endoplasmic reticulum. d. does not occur until the small subunit binds to the mRNA in the nucleus. e. does not occur until the small subunit binds to the mRNA in the cytoplasm. - CORRECT ANSWER Occurs in the nucleus As described in class, during transcription of a certain gene, the RNA polymerase will transcribe a. both strands, but only one RNA molecule will be used. b. only one of the DNA strands, moving in a 3' to 5' direction along the template. c. both strands, but moving 3' to 5' for one and 5' to 3' along the other. d. only the exons of the gene while skipping over the introns. e. Both a and c are correct answers. - CORRECT ANSWER Only one of the DNA strands, moving in a 3' to 5' direction along the template What kind of bond is characterized by the sharing of electrons? a. ionic bond b. polar covalent bond c. H-bond d. nonpolar covalent bond e. Both b and d are correct answers. - CORRECT ANSWER Both polar covalent bond and non-polarcovalent bond If the 5-carbon sugar shown in Figure 1 was part of a nucleotide used to make a/an __________, the number __________ carbon would be bonded to a phosphate? (Note this nucleotide is located in the middle of the nucleic acid and not at either end.) a. RNA,5' b. RNA,3' c. DNA 5' d. DNA, 3' e. Both a and b are correct answers. - CORRECT ANSWER Both RNA 5' and RNA 3' The name of the 5-carbon sugar shown in Figure 1 is a. hexose. b. deoxyhexose. c. ribose. d. deoxyribose. e. quintose. - CORRECT ANSWER Rhode How many amino acids are coded for by this mRNA sequence: CGUCGUUACACG? a. Three b. Four c. Five d. Ten e. Twelve - CORRECT ANSWER Four During translation, chain elongation continues until what happens? a. No further amino acids are needed by the cell. b. All tRNAs are empty. c. The polypeptide is long enough. d. A stop codon is encountered. e. The ribosomes run off the end of mRNA. - CORRECT ANSWER A stop codon is encountered Genetic information in DNA is transferred to RNA strands during a. replication. b. transcription. c. translation. d. protein synthesis. e. Both c and d are correct answers. - CORRECT ANSWER Transcription If a DNA strand has the sequence 5'-TACTTG-3', what will the nucleotide sequence be on the mRNA during transcription? a. 5'-AUGAAC-3' b. 5'-ATGAAC-3' c. 3'-AUGAAC-5' d. 3'-ATGAAC-5' e. 3'-CAAGUA-5' - CORRECT ANSWER 3'-AUGAAC-5' The major carbohydrate found in milk is a __________ and is named __________. a. polysaccharide,glucose b. monosaccharide, glucose c. disaccharide, glucose d. disaccharide, lactose e. disaccharide, sucrose - CORRECT ANSWER disaccharide, lactose Which of the following biological polymers is mismatched with its monomer? a. DNA - nucleotide b. enzyme - amino acid c. cellulose - monosaccharide d. glycogen- amino acid e. protein - amino acid - CORRECT ANSWER glycogen- amino acid Some common polypeptide _____________ structures are a helices and b sheets and these are stabilized primarily by _____________ bonds. a. tertiary, ionic b. tertiary, van der Waals c. primary, hydrogen d. secondary, hydrogen e. secondary, ionic - CORRECT ANSWER secondary, hydrogen Many types of cells have stores of lipids in their cytoplasm, usually seen as fat droplets. What is the lipid most commonly found in these droplets? a. cholesterol b. freeunsaturatedfattyacids c. free saturated fatty acids d. triacylglycerol e. phospholipids - CORRECT ANSWER Triacylglycerol snRNAs ___________________. 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. e. None of the above are correct answers. - CORRECT ANSWER can bind to specific sequences at intron-exon boundaries through complementary base-pairing. Which of the following is NOT a function of RNA in the cell? a. recognize intron splice sites b. catalyze peptide bond formation c. specify the order of nucleotides during transcription d. ribosome structure e. recognize the mRNA codons - CORRECT ANSWER specify the order of nucleotides during transcription All of the following are transcribed from DNA EXCEPT a. protein b. exons c. rRNA d. tRNA e. mRNA - CORRECT ANSWER Protein __________ disulfide bonds form between __________ amino acids located in a polypeptide. a. Covalent, cysteine b. Noncovalent, cysteine c. Covalent, methionine d. Noncovalent, methionine e. Covalent,serine - CORRECT ANSWER Covalent, cysteine A __________ is a molecule comprised of glycerol + 2 fatty acids + phosphate group + polar head group. a. cholesterol b. maltose c. triacylglycerol d. phospholipid e. polardiglyceride. - CORRECT ANSWER phospholipid Interactions between amino acid R-groups are important in determining both the __________ and __________ structure of a protein. a. primary, secondary b. secondary, tertiary c. tertiary, quaternary d. primary, tertiary e. secondary, quaternary - CORRECT ANSWER tertiary, quaternary Parts of a polypeptide that can fold independently of the rest of the molecule are called a. allosteric regions. b. catalytic sites. c. domains d. primary structures. e. exons. - CORRECT ANSWER domains Adenine forms __________ H-bonds with thymine; guanine forms __________ H- bonds with cytosine. a. two,two b. three, three c. two, three d. three, two e. three, no - CORRECT ANSWER two, three Which of the following helps to stabilize mRNA by inhibiting its degradation? a. TATA box b. spliceosomes c. 5' cap d. poly-A tail e. Both c and d are correct answers. - CORRECT ANSWER Both c and d are correct answers. Which one of the following statements about nucleosomes is FALSE? a. They are found in euchromatin. b. They are composed of both proteins and DNA. c. They are found in heterochromatin. d. They are found only on mitotic chromosomes. e. They contain histones. - CORRECT ANSWER They are found only on mitotic chromosomes. The nucleolus is a. a region of the nucleus where rRNA genes are concentrated. b. the most basic structural unit of chromatin and contains histones. c. a region of the nucleus where the large and small subunits of ribosomes bind to each other. d. a region of the nucleus where the rRNAs and proteins assemble the large and small ribosomal subunits. e. Both a and d are correct answers. - CORRECT ANSWER Both A and C During transcription a. an RNA polymerase moves along the template strand DNA in the 5' to the 3' direction. b. the 3' end of the RNA molecule is produced first. c. an RNA polymerase must first bind to a promoter sequence. d. transcription is always initiated at a "start codon." e. the RNA polymerase moves upstream as it transcribes the DNA. - CORRECT ANSWER an RNA polymerase must first bind to a promoter sequence. __________ transcribes mRNA; __________ transcribes tRNA. a. RNA polymerase II; RNA polymerase II b. RNA polymerase II; RNA polymerase III c. RNA polymerase II; RNA polymerase I d. RNA polymerase I; RNA polymerase II e. RNA polymerase I; RNA polymerase III - CORRECT ANSWER RNA polymerase II; RNA polymerase III The nucleic acid sequence TATA is a. common in chromosome telomeres. b. common in chromosome centromeres. c. RNA sequences at intron/exon splice sites. d. DNA sequences at intron/exon splice sites. e. DNA sequences in the promoter region of a gene. - CORRECT ANSWER DNA sequences in the promoter region of a gene. A particular eukaryotic protein is 300 amino acids long. Which of the following is the number of nucleotides in the DNA that codes for the amino acids in this protein? a. 3 b. 100 c. 300 d. 900 e. 1,800 - CORRECT ANSWER 900 Which of the following is a possible function of the 5'-methylguanosine cap on mature mRNAs? a. It may prevent exonuclease digestion of the 5' end of the mRNA. b. It may aid in the transport of the mRNA out of the nucleus. c. It may play an important role in the initiation of mRNA translation. d. It may allow for attachment of the small ribosomal subunit in the nucleus. e. Answers a, b and c are correct. - CORRECT ANSWER A, B and C are correct __________ are macromolecular complexes that bind to hnRNA and function to remove introns. a. Splicers b. sBURPS c. Spliceosomes d. Splicing bodies e. Splice engines - CORRECT ANSWER Spliceosomes How does the bound IRP (iron regulatory protein) prevent translation? a. It causes degradation of the mRNA by exonucleases. b. It causes degradation of the mRNA by endonucleases. c. It interferes physically with the binding of a ribosome to the 5' end of the ferritin mRNA. d. It interferes physically with the binding of a ribosome to the 3' end of the ferritin mRNA. e. It condenses the mRNA and causes it to bind to histones. - CORRECT ANSWER It interferes physically with the binding of a ribosome to the 5' end of the ferritin mRNA. Which of the following types of mutations is MOST LIKELY to be harmful? a. The insertion of 3 nucleotides into an exon of a gene. b. The insertion of 3 nucleotides into an intron of a gene. c. The insertion of 1 nucleotide into an exon of a gene. d. The insertion of 1 nucleotide into an intron of a gene. e. None of the other answers would likely be harmful. - CORRECT ANSWER The insertion of 1 nucleotide into an exon of a gene. Which of the following protein complexes would you expect to find in a protein- coding gene that is in the elongation phase of transcription? a. carboxyterminal domain (CTD)-phosphorylated RNA polymerase II associated with TFIIH. b. unphosphorylated RNA polymerase II associated with TFIIH. c. unphosphorylated RNA polymerase II associated with TATA binding protein. d. RNA polymerase III and TFIIH. e. phosphorylated RNA polymerase II and TFIID - CORRECT ANSWER carboxyterminal domain (CTD)-phosphorylated RNA polymerase II associated with TFIIH. Which of the following is NOT a correct statement about aminoacyl-tRNA synthetases? a. Each aminoacyl synthetase is specific for a given amino acid. b. The aminoacyl synthetase activity for a given amino acid can recognize only one tRNA molecule that is specific for that amino acid. c. The aminoacyl synthetase activity for a given amino acid can recognize all of the tRNA molecules that are specific for that amino acid. d. Aminoacyl synthetases use the energy from GTP to covalently link an amino acid to the corresponding tRNA. e. Both b and d are incorrect statements. - CORRECT ANSWER Both B and D are incorrect Which of the following codons could be recognized by the same tRNA due to wobble base pairing? a. AUG and UGG b. CUA and CUG c. AAA and UUU d. UAG and UGA e. AUG and AGU - CORRECT ANSWER CUA and CUG During translation a. the peptide is 'delivered' from the tRNA in the P-site to the tRNA in the A-site. b. incoming tRNAs must first bind to the E-site. c. initiation begins with the binding of the ribosomal small subunit to the poly-(A) tail of the mRNA. d. initiation begins with the large subunit binding the poly-(A) tail of the mRNA. e. the mRNA is translated by one ribosome at a time. - CORRECT ANSWER the peptide is 'delivered' from the tRNA in the P-site to the tRNA in the A-site. Choose the answer that correctly names all three of the molecules that must be bound to amino acyl-tRNA synthetase as part of its function. a. Amino acid, mRNA, tRNA b. Amino acid, rRNA, tRNA c. Amino acid, tRNA, ATP d. Amino acid, mRNA, ATP e. Amino acid, rRNA, ATP - CORRECT ANSWER Amino acid, tRNA, ATP Base-pair substitutions involving the third base of a codon are UNLIKELY to result in an error in the polypeptide. This is because a. substitutions are corrected before transcription begins. b. substitutions are restricted to introns. c. the base-pairing rules are less strict for the third base of codons and anticodons. d. a signal-recognition particle corrects coding errors. e. transcribed errors attract snRNPs, which then stimulate splicing and correction. - CORRECT ANSWER the base-pairing rules are less strict for the third base of codons What is the relationship among DNA, a gene, and a chromosome? a. A chromosome contains hundreds of genes, which are composed of protein. b . A chromosome contains hundreds of genes, which are composed of DNA. c. A gene contains hundreds of chromosomes, which are composed of protein. d. A gene is composed of DNA, but there is no relationship to a chromosome. e. A gene contains hundreds of chromosomes, which are composed of DNA. - CORRECT ANSWER A chromosome contains hundreds of genes, which are composed of DNA. The strands that make up DNA are antiparallel. This means that a. the twisting nature of DNA creates nonparallel strands. b. the 5' to 3' direction of one strand runs opposite to the 5' to 3' direction of the other strand. c. base pairings create unequal spacing between the two DNA strands. d. one strand is positively charged and the other is negatively charged. e. one strand contains only purines and the other contains only pyrimidines. - CORRECT ANSWER the 5' to 3' direction of one strand runs opposite to the 5' to 3' direction of the other strand. Which of the following represents a similarity between RNA and DNA? a. Both are always double-stranded. b. the presence of uracil c. the presence of an OH group on the 2' carbon of the sugar d. nucleotides consisting of a phosphate, sugar, and nitrogenous base e. Both are found exclusively in the nucleus. - CORRECT ANSWER nucleotides consisting of a phosphate, sugar, and nitrogenous base Accuracy in the translation of mRNA into the primary structure of a protein depends on specificity in the a. binding of ribosomes to mRNA. b. shape of the A and P sites of ribosomes. c. bonding of the anticodon to the codon. d. attachment of amino acids to tRNAs. e. Both c and d are correct answers. - CORRECT ANSWER C and D are correct In figure 2 the DNA sequences labeled "1" are a. euchromatic. b. centromeric DNA. c. teleomeric DNA. d. lagging strands. e. Both b and c are correct answers. - CORRECT ANSWER teleomeric DNA. In figure 2, the DNA sequences labelled "2" are a. origins of replication. b. centromericDNA. c. teleomericDNA. d. lagging strands. e. Both a and d are correct answers. - CORRECT ANSWER Origins of replication In figure 2, the DNA sequences labelled "3" are a. origins of replication. b. centromericDNA. c. teleomericDNA. d. TATA boxes. e. Both c and d are correct answers. - CORRECT ANSWER Centromeric DNA In figure 2, the stage of the cell cycle labelled "X" is __________, while the stage of the cell cycle labelled "Y" is a. M phase, interphase b. Interphase, M phase c. Intraphase, M phase d. M phase, Intraphase e. None of the other answers are correct. - CORRECT ANSWER Interphase, M phase