Exam 1 for BIOL 2104. Garded A

Multiple choice questions 1 — 25. INDICATE YOUR ANSWERS ON THE OP- SCAN SHEET. (2 points each) 1. Which of the following is the smallest in width? a. 30 nm fiber b. chromosome c. double-stranded DNA d. nucleosome ...

Multiple choice questions 1 — 25. INDICATE YOUR ANSWERS ON THE OP- SCAN SHEET. (2 points each) 1. Which of the following is the smallest in width? a. 30 nm fiber b. chromosome c. double-stranded DNA d. nucleosome 2. The genetic code is degenerate. This means that for each tRNA: a. there is more than one amino acid b. there is more than one codon c. there is more than one amino acid and more than one codon d. there is only one amino acid and only one codon 3. Which of the following statements is/are true? a. Plant and animal cells have fundamental similarities, especially during development. b. All cells possess a nucleus. c. Cells arise by spontaneous generation. d. a and b e. all of the above 4. Which of the following amino acids introduces kinks or bends in a protein? a. methionine b. proline c. valine d. all of the above e. none of the above 5. Which enzyme attaches phosphate groups to proteins? a. kinase b. ligase c. nuclease d. phosphatase e. polymerase For questions 6-8, refer to the diagram below. 0 HNC SC 2 3 '1 O 0 0 -0-P-0-0 P 0 0 P 0 0 0 0 6. Name the base. a. adenine b. cytosine c. guanine d. thymine e. uracil H OH 2 OH 7. How many hydrogen bonds will this nucleotide form with its complement.. a. 0 b. 1 c. 2 d. 3 e. 4 8. Is this nucleotide a component of DNA or RNA? a. DNA b. RNA c. neither d. both 9. Reverse transcriptase catalyzes the synthesis of from a template a. DNA, DNA b. RNA, RNA c. RNA, DNA d. DNA, RNA e none of the above 10. Which of the following amino acids can be phosphorylated? a. phenylalanine b. threonine c. tryptophan d. b and c e. all of the above 11. Which of the following organisms has the smallest genome? a. Arabadopsis thaliana b. Dictyastelium discoideum c. Homo sapiens d. Mus musculus e. Saccharomyces cerevisiae 12. Which of the following contain a hydroxyl (OH) in the 3'position? a. ATP b. dATP c. ddATP d. a and b e. b and c 13. In the Watson and Crick model, DNA replication is: a. semi-conservative b. 3' - > 5' c. catalyzed by reverse transcriptase d. a and b e. a and c 14. Which type of microscopy would give the best resolution of the mitochondria in a thin section of a liver cell? a. brightfield microscopy b. confocal microscopy c. differential interference contrast (DIC) microscopy d. scanning electron microscopy e. transmission electron microscopy 15. In what order are the following enzymatic activities required for DNA replication on the lagging strand? a. DNA polymerase, RNA polymerase, DNA polymerase, RNase, ligase b. RNA polymerase, DNA polymerase, RNase, DNA polymerase, ligase c. RNA polymerse, RNase, DNApolymerase, ligase, DNA polymerase d. DNA polymerase, RNAse, DNA polymerase, RNA polymerase, ligase e. DNA polymerase, RNase, RNA polymerase, DNA polymerase, ligase 16. Who is/are credited with observing and naming the first cells? a. Hooke b. Prusiner c. Schleiden and Schwann d. Temin and Baltimore e. Watson and Crick 17. Genes that are expressed are: a. achromatic b. dichromatic c. euchromatic d. heterchromatic e. monochromatic 18. In a chemical reaction, enzymes alter the free energy of the: a. substrate b. product c. transition state d. a and b e. all of the above 19. Which of the following techniques requires a microscope. a. density gradient centrifugation b. karyotyping c. making a cDNA library d. b and c e. all of the above 20. Name the vertebrate model organism best suited for studies of genetics and developmental biology. a. Danio rario b. Drosophila inelanogaster c. Escherichia coli d. Saccharoinyces cerevisiae e. Xenopus laevis 21. Which of the following is a covalent bond that can form between any two amino acids? a. disulfide bond b. hydrogen bond c. ionic bond d. peptide bond e. phosphodiester bond 22. Which technique could be used to separate mitochondria from lysosomes? a. brightfield microscopy b. density gradient centrifugation c. FISH d. PCR e. none of the above 23. Name the type of microscopy that would be best used to observe the transport of GFP-labeled proteins along microtubule motors in cultured epithelial cells. a. bright-field b. lfuorescence confocal c. differential interference contrast (DIG) d. scanning EM e. transmission EM 24. Which of the following pairs of enzymes catalyze opposite reactions? a. kinase/nuclease b. kinase/protease c. ligase/nuclease d. ligase/protease e. nuclease/protease 25. The TATAA box is a: a. cis element b. trans-acting factor c. both a cis element and a trans-acting factor d. neither a cis element nor a trans-acting factor Short answer questions 25 — 34, Answer questions in the space provided. (5 pts each) 26. How can one distinguish between promoter and enhancer elements? An enhancer can be moved or lapped in orientation and OM affect transcription whereas a promoter is distance- and orientation- dependent. if a promoter is moved or Mooed, there wilt be no transcription. 27. Name three processing events that a primary mRNA transcript is subjected to before it is exported from the nucleus as a mature mRNA. 1. addition of a 5' cap (7-me-thy(guanosIne) 2.. spacing out of introits 3. addition of a poly A tar( to the 3' end 28. Name 4 forces that drove the evolution of the first cell. Need for flexible yet stable genetic materra( Weed to use energy to fight entropy Weed for a boundary Need to reproduce (lots of other good answers too) 5 29. Why do tRNAs frequently contain an inosine in the anti-codon loop? The genetic code is degenerate, with more than one colon per amino acid. Since inosine can ()ace pair with muttipte nucleic acids, a +RNA with inosine in the "wobble" position will allow the same +RNA to recognize more than one colon for the same amino acid. 30. Name three advantages to performing research on a limited number of model organisms. Name a disadvantage. See quiz 1- there are tots of good answers 31. Why is the resolution of the modern light microscope no better than that of the microscopes used by Robert Hooke? Resotution is limited by the wavelength of light, which is fixed and the nuiv•erica( aperature, which can only be made so slv•a((. 32. Explain primary, secondary, tertiary and quaternary structure of a protein. - the linear sequence of amino acids in a potypeptide chain 2° - short regions of three dimensional shape (e.g. aloha hetices and ()eta sheets) 3°- the three dimensional structure of an entire potypeptide chain 1°- the three-dimensionat association of more than one Pots/Peptide into a functiona( protein 33. Define chromatin. ChroMatin is WA and its associated proteins. 34. When the scientist Okazaki discovered his famous fragments on the lagging strand of replicating DNA, he helped to resolve a major puzzle regarding the mechanism by which DNA polymerase simultaneously replicates both strands of DNA. What is the puzzle that his discovery helped to resolve? The puzzle was how both strands of WA were replicated 5' to 3' when they were oriented in opposite directions and the replication fork with DMA potymerase only moves in one direction.