Genetics and Molecular Biology: DNA Replication, Transcription, and Protein Synthesis - Pr, Exams of Cellular and Molecular Biology

Download Genetics and Molecular Biology: DNA Replication, Transcription, and Protein Synthesis - Pr and more Exams Cellular and Molecular Biology in PDF only on Docsity!

Biology 150: Principles of Cellular and Molecular Biology December 15, 2009 Final Exam Please fill in your name and ID no. on the answer sheet. Be sure to darken the circles beneath your name and ID number. There are 62 questions on this Final Exam. Questions 1-38 are multiple choice while questions 39-62 are true/false questions. Please enter the code for this exam (provided at the bottom on the last page of the exam) on your scantron sheet (left most column of CODES section). The code will either be the number 1, 2, 3 or 4. It is critical that you darken the appropriate circle so that your exam will be scored correctly. Part I (Unit IV). Provide all answers on the scantron answer sheet. If the question is of multiple choice format, please choose the best answer from the responses that are given. Darken the circle on the answer sheet completely. (2 points per question) Questions numbered 1 through 4 refer for the following genetic cross in fruit flies.  Absence of bristles on the legs is the wild type phenotype ( b+ ) / recessive mutant phenotype is legs with bristles ( b )  Smooth wings is the wild type phenotype ( n+ ) / recessive mutant phenotype is notched wings ( n ) A heterozygote for these two characteristics ( b+b n+n ) is mated with an organism that is a double mutant (i.e., homozygous recessive for both characteristics). Four combinations of phenotypes (labeled as A, B, C, and D below) appear in the offspring: A. absence of bristles on the legs / smooth wings B. absence of bristles on the legs / notched wings C. bristles on the legs / smooth wings D. bristles on the legs / notched wings

1. Which of the above phenotypes are considered parental phenotypes? a. A and B b. A and C c. B and C d. A and D e. B and D

2. If the genes for these two characteristics are NOT linked then the percentage of the total offspring expressing the C phenotype would be a. 0% b. 25% c. 50% d. 75% e. 100%
3. If the two genes are linked, then the percentage of offspring with the A phenotype would be a. greater than the percentage of offspring expressing the A phentotype if the genes were NOT linked b. less than the percentage of offspring expressing the A phentotype if the genes were NOT linked c. equal to the percentage of offspring expressing the A phentotype if the genes were NOT linked
4. Recombination of linked genes occurs by: a. independent assortment of homologous chromosomes during meiosis b. crossing over between non-sister chromatids of a homologous pair of chromosomes c. the random nature of fertilization whereby an individual egg is randomly fertilized by a sperm from among a large number of sperm
5. A woman who has type A blood has a child with blood type O. Which of the following blood types could the father not be? a. A b. B c. O d. AB

Questions 6 through 9 refer to one of the following terms. Each term may be used once, more than once, or not at all. a. pleiotropy b. epistasis c. complete dominance d. incomplete dominance e. codominance

6. One example is the ABO blood group system E
7. The phenotype of the heterozygote is an intermediate (e.g., pink) between the phenotypes of both homozygotes (e.g., red and white). D
8. A gene at one locus alters the phenotypic expression of a gene at a second locus B
9. A single gene leads to multiple phenotypes. A
10. An anticodon is a base triplet within what molecule? a. template stand of DNA b. non-template strand of DNA c. mRNA d. tRNA e. rRNA
11. A codon has a base sequence of UUA. What is the base sequence of the triplet in the non-template strand of DNA that coded for the synthesis of this codon? a. UUA b. AAT c. TTA d. UUT e. GGC
12. If the sequence of bases for in the template strand of DNA is TCA what is the base sequence for the anticodon that binds to the codon expressed by this DNA triplet? a. AGU b. TCA c. UCA d. TCU e. UUA

The above diagram represents a bubble for DNA replication. Questions 13 and 14 refer to this diagram.

13. Which of the above letters labels the 5' end of one strand of the parent DNA molecule? a. A b. B c. C d. D
14. Which of the above letters designates the leading strand for DNA synthesis? a. C b. D c. Both C and D d. Neither C nor D
15. Transcription factors a. are proteins that assist in the binding of RNA polymerase to DNA and initiation of transcription from the transcription start and assist with initiation of transcription b. are proteins that are required for the termination of transcription c. are segments of the template strand of DNA and that are located upstream from the transcription start point and assist with initiation of transcription d. are segments of the non-template strand of DNA that are located upstream

16. If guanine comprises 32% of the nitrogenous bases in a sample of DNA, then what is the percentage of adenine nucleotides in this DNA sample? a. 64% b. 36% c. 18% d. 9% e. the percentage adenine nucleotides cannot be calculated with the information that is provided
17. Which of the following molecules or functional groups is NOT present within RNA? a. ribose b. deoxyribose c. guanine d. uracil e. phosphate group
18. Which of the following statements best defines the antiparallel nature of DNA structure? a. the non-template strand is always complementary to the template strand of DNA b. the alpha helix coils clockwise for one strand and counterclockwise for the complementary strand c. if the base sequence of one strand is known, then the base sequence of the complimentary strand can be determined d. a purine base within one strand is always paired with a pyrimidine base within the complimentary strand e. the orientation of the pentose sugars is reversed in one strand compared to the complementary strand
19. What type of chemical bonds or interactions joins guanine and cytosine in the DNA double helix? a. hydrogen bonds b. ionic bonds c. polar covalent bonds d. nonpolar covalent bonds e. van der Wahls interactions

The following enzymes participate in DNA replication. Please use the appropriate designated letter for each enzyme to answer the following questions numbered 20 through 22. ligase = a single stand binding protein = b DNA polymerase III = c DNA polymerase I = d

20. Stabilizes DNA strand after double stranded molecule has been unwound B
21. Enzyme that joins Okazaki fragments A
22. Enzyme that removes RNA nucleotides and replaces these nucleotides with DNA nucleotides D
23. Which of the following is required for the start or initiation of DNA synthesis? a. promoter region of DNA b. transcription factors c. short segment of RNA d. short segment of DNA e. DNA ligase
24. The base sequence AAUAAA is a sequence of bases a. in the template strand of DNA that signals termination of transcription b. in the non-template strand of DNA that signals termination of transcription c. in the primary RNA transcript that signals termination of transcription d. in mRNA that signals the termination of translation
25. Approximately how many base pairs long is an mRNA transcript that codes for a 150 amino acid polypeptide? a. ~ 50 nucleotides long b. ~ 150 nucleotides long c. ~ 250 nucleotides long d. ~ 350 nucleotides long e. ~ 450 nucleotides long

26. tRNA shifts position within the ribosome during translation. Which of the following sequence of events is correct? a. attachment of growing polypeptide to the single amino acid on tRNA  bonding of the tRNA anticodon to the codon of mRNA  shift of tRNA from A to P site of ribosome b. bonding of the tRNA anticodon to the codon of mRNA  shift of tRNA from A to P site  attachment of growing polypeptide to the single amino acid on tRNA c. bonding of the tRNA anticodon to the codon of mRNA  attachment of growing polypeptide to the single amino acid on tRNA  shift of tRNA from A to P site d. bonding of the tRNA anticodon to the codon of mRNA  shift of tRNA from P to A site  attachment of growing polypeptide to the single amino acid on tRNA
27. DNA polymerase III is an enzyme that a. removes introns from the pre-mRNA in eukaroytic b. catalyzes the addition of nucleotides to the 3’ end of the growing strand of DNA c. catalyzes the addition of nucleotides to the 5’ end of the growing strand of DNA d. catalyzes the addition of a 3’ cap to the new strand of DNA e. splices exons following removal of introns from pre-mRNA
28. The codon UGG codes for the amino acid tryptophan. This codon a. may also code for another amino acid b. will only code for tryptophan c. binds to the TCC anticodon d. is coded by a AGG triplet within the template strand of DNA e. is a start codon for translation
29. Indicate a difference between pre-mRNA and mRNA. a. pre mRNA contains exons; mRNA contains no exons b. pre mRNA leaves the nucleus of eukaryotic cells; mRNA does not leave the nucleus c. pre mRNA contains introns; mRNA contains no introns d. pre mRNA has a repeated adenine nucleotide sequence at the 5’ end of the molecule; mRNA does not have this AAAA repeat sequence at the 5’ end e. pre mRNA contains thymine bases; mRNA does not contain thymine bases
30. The large and small subunits of the ribosome a. utilize energy in the form of ATP to join during the initiation of translation b. join during the elongation of transcription c. are never separated within the cytoplasm of eukaryotic cells d. utilize energy in the form of GTP to join during the initiation of translation

31. If two genes for seed color or seed appearance are not linked, how many different gametes can result from a parental genotype of YYRr? a. 1 b. 2 c. 3 d. 4
32. Mendel's dihybrid cross in pea plants provided evidence for the independent assortment of alleles for an individual genetic character. The random event is due to a. crossing over b. random alignment of tetrads on the metaphase plate during Meiosis I c. linkage of genes on the same chromosome d. pairing of duplicated homologous chromosomes during prophase of Meiosis I
33. The stop codons a. also code for glycine b. also code for serine c. also code for phenylalanine d. also code for methionine e. do not code for an amino acid
34. In eukaryotic cells, RNA polymerase a. adds nucleotides to the 5' end of the growing RNA transcript b. removes introns from the primary RNA transcript c. adds a polyA tail to the 3' end of the RNA transcript d. adds nucleotides to the 3' end of the growing RNA transcript e. joins exons following removal introns from the primary RNA transcript
35. With regards to base nucleotide composition of DNA, which of the following statements is true? a. A + U = G + C b. A = G and C = T c. A + T = G + C d. A + G = T + C

36. The TATA box is a. a protein that assists with the binding of RNA polymerase to DNA b. a base sequence within the transcription unit of DNA c. a codon that signals the termination of transcription d. a base sequence within the non-template strand of DNA that is upstream from the transcription start point and assists with the binding of RNA polymerase e. a base sequence within the template strand of DNA that is upstream from the transcription start point and assists with the binding of RNA polymerase
37. The term wobble refers to a relaxation of base pairing rules for a. the synthesis of the lagging strand of DNA b. the transcription of pre-mRNA in prokaryotic cells c. the binding of anticodons to codons d. the removal of introns during RNA splicing
38. A release factor a. binds to the A site of the ribosome during the initiation of translation b. binds to the P site of the ribosome during the termination of translation c. binds to the E site site of the ribosome during the termination of translation d. binds to the A site of the ribosome during the termination of translation Part II. Comprehensive final. For the statements below, darken ‘a’ if the statement is true. Darken ‘b’ if the statement is false. (1 point per question)
39. In a triglyceride, a glycosidic bond links fatty acids to the glycerol molecule. B
40. A hydrogen bond is a weak bond that forms between the hydrogen atom of one polar molecule and an electronegative atom on a second polar molecule. A
41. Phospholipids are molecules that have both hydrophobic and hydrophilic properties. A
42. Methane (CH 4 ) has a double bond between one of the hydrogen atoms and carbon. B
43. The C terminus end of a protein consists of a carbonyl group.B
44. The hydrogen ion concentration of a solution with a pH of 7 is 10-7^ M.A
45. Amino acids can be grouped as polar, non-polar or ionic based on the properties of the R groups or side chains of the amino acid.A

46. The covalent bonds between hydrogen and oxygen in water are non-polar covalent bonds.B
47. Enzymes speed up chemical reactions by lowering the energy of activation for chemical reactions.A
48. For integral membrane proteins, the amino acids that are located within the lipid bilayer have hydrophobic properties.A
49. Proteins that are secreted by the cell are synthesized by ribosomes that are attached to the cytoplasmic surface of the endoplasmic reticulum.A
50. Photosynthesis occurs within the mitochondria of plant cells.B
51. The source of oxygen within the light dependent reactions of photosynthesis is water.A
52. The majority (greater than 50%) of the ATP produced during the metabolism of glucose is produced during glycolysis.B
53. During cellular respiration, CO 2 is produced during the Krebs or Citric Acid cycle.A
54. The final electron acceptor in the electron transport chain during cellular respiration is O 2 .A
55. In Mendel's monohybrid cross, the recessive phenotype was absent in the F generation but reappeared in the offspring of the F2 generation.A
56. The enzyme that catalyzes the fixation of CO 2 in the Calvin cycle is rubisco.A
57. G proteins are activated when bound to GTP and deactivated when bound to GDP.A
58. The production of IP 3 leads to the release of calcium from intracellular calcium stores.A
59. A drug that inhibits the action of adenylyl cyclase will prevent the conversion of ATP to cyclic AMP.A
60. Protein kinases catalyze the phosphorylation of proteins.A
61. Homologous chromosomes are separated into different daughter cells during meiosis leading to haploid cells.A
62. Synapsis or pairing of homologous chromosomes occurs during meiosis but not during mitosis.A

• CODE =