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  1. 1. THE GENETIC CODE ANDTRANSCRIPTION PRACTICE QUIZ GENETIC CODE 1. Crick demonstrated that the genetic code involved three bases and suggested that the code was degenerate. What experimental technique did he use? A. Gel electrophoresis B. Density gradient centrifugation C. Frameshift mutagenesis D. Restriction digests of the rII gene 2. The first breakthrough leading to "breaking the code" was by Nirenberg and Matthaei in 1961. They used which of the following techniques to determine the first codon A. In vitro synthesis of a polypeptide using UUUUU B. Labeled peptide binding to a ribosome C. Mixed co-polymer mRNA synthesis 3. The genetic code is degenerate. Which of the following codons represents the principle of degeneracy? A. UAA and UAC B. AUG and AUA C. CAU and CAC D. UUA and UUC 4. In prokaryotes, AUG encodes - A. Methionine B. N-formyl methionine C. A stop codon 5. How many amino acids will the following sequence encode? 5' GAU GGU UGA UGU 3' A. One
  2. 2. B. Two C. Three D. Four 6. The genetic code is - A. Universal B. Universal except for rare exceptions in mitochondria and some protozoa C. Species-specific D. Kingdom-specific TRANSCRIPTION 1. RNA polymerase in prokaryotes has a removable - A. Alpha subunit B. Beta subunit C. Sigma subunit* 2. There are several different forms of sigma that are specific for different genes, A. True B. False 3. Upstream regions which are essential for corret transcription are called - A. Enhancers B. Start codons C. Promoters D. Transcription factors 4. A promoter region that is rich in AT bases is called the ______ box in both eukaryotes and prokaryotes A. CATT B. Shine Dalgarno region C. TATA box
  3. 3. D. SV40 region 5. In eukaryotes, there are three different RNA polymerases. The RNA polymerase responsible for transcription of mRNA is ___ A. RNA polymerase I B. RNA polymerase II* C. RNA polymerase III 6. Promoters for tRNAs are located _______ A. Upstream from the start codon B. Downstream from the start codon 7. Enhancers are regions that - A. Bind RNA polymerase B. Are adjacent to the TATA box C. CAT box binding proteins D. Modulate transcription 8. Transcription factors are __ A. Promoters B. Proteins which bind to DNA and regulate transcription C. TATA boxes D. CATT boxes 9. Transcription begins _____ A. At the start codon B. Upstream from the start codon C. Downstream from the start codon 10. In prokaryotes, transcription is ___ A. Terminated by the stop codon B. Terminated by a protein called rho
  4. 4. C. Terminated by a poly A sequence PROCESSING 1. The non-coding DNA regions within a gene are called A. Exons B. Introns C. Poly A D. Splicosomes 2. Group III introns are -- A. Self-splicing B. Require a splicosome to remove them C. Are translated on the ribosomes 3. In eukaryotes, which of the following is added to the 5' end of the mRNA? A. Poly A B. 7-methyl guanosine C. Exons D. Ribozymes 4. Which of the following is not a part of eukaryotic mRNA modification? A. Removal of exons B. Capping with 7-MG C. Adding a poly A tail D. Altering or adding RNA bases 5. When mRNA is procesed, it moves through the nuclear membrane to the cytoplasm. A. True B. False TRANSLATION 1. The ribosomes are composed of ____
  5. 5. A. Proteins B. RNA C. Both of the above 2. Which of the following RNAs binds to an amino acid? A. mRNA B. tRNA C. rRNA D. hnRNA 3. The anticodon of tRNA ----- A. Binds to rRNA B. Binds to an amino acid C. Binds to the Shine Dalgarno sequence D. Binds to an mRNA codon 4. Which of the following has unusual bases such as inosine? A. mRNA B. tRNA C. rRNA D. mRNA 5. True or false? All tRNAs are charged by a single aminoacyl synthetase. A. True B. False 6. The first step in translation is A. Binding of the two ribosomal subunits to each other B. Binding of mRNA to the two ribosomal subunits C. Binding of tRNA to the small ribosomal subunit
  6. 6. D. Binding of mRNA to the small ribosomal subunit 7. Eukaryotic mRNA binding to the ribosomes is facilitated by ___ A. The Shine Dalgarno sequence B. The 7-methyl guanosine cap C. tRNA D. Poly A tail 8. The growing polypeptide chain is released from the ribosomes when -- A. A chain terminating codon is reached B. A chain terminating tRNA binds to the ribosome C. The 7-methyl guanosine cap is reached D. The poly A tail is reached 9. The direction of amino acid transfer to the growing polypeptide chain is A. From the A site to the P site on the ribosome B. From the P site to the A site on the ribosome