Chapter 13 The Genetic Code and Transcription1) When considering the initiation of transcription, one often finds consensus sequences located in the region of the DNA where RNA polymerase(s) binds. Which of the following is a common consensus sequence?A) TATAB) GGTTCC) TTTTAAAAD) any trinucleotide repeatE) satellite DNAsAnswer: ASection: 13.102) What is the name given to the three bases in a messenger RNA that bind to the anticodon of tRNA to specify an amino acid placement in a protein?A) proteinB) anti-anticodonC) cistronD) rhoE) codonAnswer: ESection: 13.123) An intron is a section of ________.A) protein that is clipped out posttranslationallyB) RNA that is removed during RNA processingC) DNA that is removed during DNA processingD) transfer RNA that binds to the anticodonE) carbohydrate that serves as a signal for RNA transportAnswer: BSection: 13.124) The genetic code is fairly consistent among all organisms. The term often used to describe such consistency in the code is ________.A) universalB) exceptionalC) trans-specificD) overlappingE) none of the aboveAnswer: ASection: 13.61Copyright © 2012 Pearson Education, Inc.5) Which of the following two terms relate most closely to split genes?A) 5'-cap, 3'-poly-A tailB) introns, exonsC) elongation, terminationD) transcription, translationE) heteroduplex, homoduplexAnswer: BSection: 13.126) Significant in the deciphering of the genetic code was the discovery of the enzyme polynucleotide phosphorylase. What is this enzyme used for?A) manufacture of synthetic RNA for cell-free systemsB) ribosomal translocationC) peptide bond formationD) production of ribosomal proteinsE) degradation of RNAAnswer: ASection: 13.37) In 1964, Nirenberg and Leder used the triplet binding assay to determine specific codon assignments. A complex of which of the following components was trapped in the nitrocellulose filter?A) ribosomes and DNAB) free tRNAsC) charged tRNA, RNA triplet, and ribosomeD) uncharged tRNAs and ribosomesE) sense and antisense strands of DNAAnswer: CSection: 13.38) What is the initiator triplet in both prokaryotes and eukaryotes? What amino acid is recruited by this triplet?A) UAA; no amino acid called inB) UAA or UGA; arginineC) AUG; arginineD) AUG; methionineE) UAA, methionineAnswer: DSection: 13.42Copyright © 2012 Pearson Education, Inc.9) Which of the following contains the three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes?A) 5'-capping, 3'-poly(A) tail addition, splicingB) 3'-capping, 5'-poly(A) tail addition, splicingC) removal of exons, insertion of introns, cappingD) 5'-poly(A) tail addition, insertion of introns, cappingE) heteroduplex formation, base modification, cappingAnswer: ASection: 13.11, 13.12, 13.1310) The genetic code is said to be triplet, meaning that there ________.A) are three amino acids per base in mRNAB) are three bases in mRNA that code for an amino acidC) may be three ways in which an amino acid may terminate a chainD) are three "nonsense" tripletsE) None of the answers listed is correct.Answer: BSection: 13.211) When scientists were attempting to determine the structure of the genetic code, Crick and coworkers found that when three base additions or three base deletions occurred in a single gene,the wild-type phenotype was sometimes restored. These data supported the hypothesis that ________.A) the code is tripletB) the code contains internal punctuationC) AUG is the initiating tripletD) the code is overlappingE) there are three amino acids per baseAnswer: ASection: 13.212) When examining the genetic code, it is apparent that ________.A) there can be more than one amino acid for a particular codonB) AUG is a terminating codonC) there can be more than one codon for a particular amino acidD) the code is ambiguous in that the same codon can code for two or more amino acidsE) there are 44 stop codons because there are only 20 amino acidsAnswer: CSection: 13.43Copyright © 2012 Pearson Education, Inc.13) The relationship between a gene and a messenger RNA is that ________.A) genes are made from mRNAsB) mRNAs are made from genesC) mRNAs make proteins, which then code for genesD) all genes are made from mRNAsE) mRNA is directly responsible for making Okazaki fragmentsAnswer: BSection: 13.814) A class of mutations that results in multiple contiguous (side-by-side) amino acid changes in proteins is probably caused by which of the following type of mutation?A) frameshiftB) transversionC) transitionD) base analogE) recombinantAnswer: ASection: 13.215) Introns are known to contain termination codons (UAA, UGA, or UAG), yet these codons donot interrupt the coding of a particular protein. Why?A) UAA, UGA, and UAG are initiator codons, not termination codons.B) Exons are spliced out of mRNA before translation.C) These triplets cause frameshift mutations, but not termination.D) More than one termination codon is needed to stop translation.E) Introns are removed from mRNA before translation.Answer: ESection: 13.416) It has been recently determined that the gene for Duchenne muscular dystrophy (DMD) is more than 2000 kb (kilobases) in length; however, the mRNA produced by this gene is only about 14 kb long. What is a likely cause of this discrepancy?A) The exons have been spliced out during mRNA processing.B) The DNA represents a double-stranded structure, whereas the RNA is single-stranded.C) There are more amino acids coded for by the DNA than by the mRNA.D) The introns have been spliced out during mRNA processing.E) When the mRNA is produced, it is highly folded and therefore less long.Answer: DSection: 13.114Copyright © 2012 Pearson Education, Inc.17) If one compares the base sequences of related genes from different species, one is likely to find that corresponding ________ are usually conserved, but the sequences of ________ are much less well conserved.A) exons; intronsB) introns; exonsC) introns; chaperonsD) chaperons; exonsE) introns; proteinsAnswer: ASection: 13.1218) In which cellular organelle do the three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes occur?A) nucleusB) cytoplasmC) mitochondrionD) lysosomeE) GolgiAnswer: ASection: 13.1219) Describe the direction of information flow in living systems. Use appropriate, scientific terms in your description.Answer: DNA is replicated and passed to offspring through a variety of reproductive processes. Information contained in the base sequences