Campbell s Biology 9e Reece et al Chapter 17 From Gene to Protein The text for Chapter 17 has remained largely unchanged from the previous edition However one third of the following questions are new and considerably more are at the skill level of analysis and application Multiple Choice Questions 1 Which of the following variations on translation would be most disadvantageous for a cell A translating polypeptides directly from DNA B using fewer kinds of tRNA C having only one stop codon D lengthening the half life of mRNA E having a second codon besides AUG as a start codon Answer A Topic Concept 17 1 Skill Application Analysis 2 Garrod hypothesized that inborn errors of metabolism such as alkaptonuria occur because A metabolic enzymes require vitamin cofactors and affected individuals have significant nutritional deficiencies B enzymes are made of DNA and affected individuals lack DNA polymerase C many metabolic enzymes use DNA as a cofactor and affected individuals have mutations that prevent their enzymes from interacting efficiently with DNA D certain metabolic reactions are carried out by ribozymes and affected individuals lack key splicing factors E genes dictate the production of specific enzymes and affected individuals have genetic defects that cause them to lack certain enzymes Answer A Topic Concept 17 1 Skill Knowledge Comprehension 3 Garrod s information about the enzyme alteration resulting in alkaptonuria led to further elucidation of the same pathway in humans Phenylketonuria PKU occurs when another enzyme in the pathway is altered or missing resulting in a failure of phenylalanine phe to be metabolized to another amino acid tyrosine Tyrosine is an earlier substrate in the pathway altered in alkaptonuria How might PKU affect the presence or absence of alkaptonuria A It would have no effect because PKU occurs several steps away in the pathway B It would have no effect because tyrosine is also available from the diet C Anyone with PKU must also have alkaptonuria D Anyone with PKU is born with a predisposition to later alkaptonuria E Anyone with PKU has mild symptoms of alkaptonuria Answer B Topic Concept 17 1 Skill Application Analysis 1 Copyright 2011 Pearson Education Inc 4 The nitrogenous base adenine is found in all members of which group A proteins triglycerides and testosterone B proteins ATP and DNA C ATP RNA and DNA D glucose ATP and DNA E proteins carbohydrates and ATP Answer C Topic Concept 17 1 Skill Knowledge Comprehension 5 A particular triplet of bases in the template strand of DNA is 5 AGT 3 The corresponding codon for the mRNA transcribed is A 3 UCA 5 B 3 UGA 5 C 5 TCA 3 D 3 ACU 5 E either UCA or TCA depending on wobble in the first base Answer A Topic Concept 17 1 Skill Application Analysis 6 The genetic code is essentially the same for all organisms From this one can logically assume which of the following A A gene from an organism can theoretically be expressed by any other organism B All organisms have experienced convergent evolution C DNA was the first genetic material D The same codons in different organisms translate into the different amino acids E Different organisms have different numbers of different types of amino acids Answer A Topic Concept 17 1 Skill Synthesis Evaluation 7 The universal genetic code is now known to have exceptions Evidence for this can be found if which of the following is true A If UGA usually a stop codon is found to code for an amino acid such as tryptophan usually coded for by UGG only B If one stop codon such as UGA is found to have a different effect on translation than another stop codon such as UAA C If prokaryotic organisms are able to translate a eukaryotic mRNA and produce the same polypeptide D If several codons are found to translate to the same amino acid such as serine E If a single mRNA molecule is found to translate to more than one polypeptide when there are two or more AUG sites Answer A Topic Concept 17 1 Skill Synthesis Evaluation 2 Copyright 2011 Pearson Education Inc 8 Which of the following nucleotide triplets best represents a codon A a triplet separated spatially from other triplets B a triplet that has no corresponding amino acid C a triplet at the opposite end of tRNA from the attachment site of the amino acid D a triplet in the same reading frame as an upstream AUG E a sequence in tRNA at the 3 end Answer D Topic Concept 17 1 Skill Application Analysis 9 Which of the following provides some evidence that RNA probably evolved before DNA A RNA polymerase uses DNA as a template B RNA polymerase makes a single stranded molecule C RNA polymerase does not require localized unwinding of the DNA D DNA polymerase uses primer usually made of RNA E DNA polymerase has proofreading function Answer D Topic Concept 17 2 Skill Application Analysis 10 Which of the following statements best describes the termination of transcription in prokaryotes A RNA polymerase transcribes through the polyadenylation signal causing proteins to associate with the transcript and cut it free from the polymerase B RNA polymerase transcribes through the terminator sequence causing the polymerase to separate from the DNA and release the transcript C RNA polymerase transcribes through an intron and the snRNPs cause the polymerase to let go of the transcript D Once transcription has initiated RNA polymerase transcribes until it reaches the end of the chromosome E RNA polymerase transcribes through a stop codon causing the polymerase to stop advancing through the gene and release the mRNA Answer B Topic Concept 17 2 Skill Knowledge Comprehension 11 Which of the following does not occur in prokaryotic eukaryotic gene expression but does in eukaryotic gene expression A mRNA tRNA and rRNA are transcribed B RNA polymerase binds to the promoter C A poly A tail is added to the 3 end of an mRNA and a cap is added to the 5 end D Transcription can begin as soon as translation has begun even a little E RNA polymerase requires a primer to elongate the molecule Answer C Topic Concept 17 2 Skill Knowledge Comprehension 3 Copyright 2011 Pearson Education Inc 12 RNA polymerase in a prokaryote is composed of several subunits Most of these subunits are the same for the transcription of any gene but one known as sigma varies considerably Which of the following is the most probable advantage for the organism of such sigma switching A It might allow the transcription process to vary from one cell to another B It might allow the polymerase to