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BIOL 286/586 Exam I October 2014 Name:____________________________________________________ Personal Information on the answer sheet --Enter your name in the boxes, fill in the corresponding circles --Sign your name at the top Test answers on the answer sheet, fill in the BEST possible answer. 01. The chemical reactivity of an atom is determined by a. the total number of neutrons in its nucleus. b. the total number of protons in its nucleus. c. the total number of electrons in its orbitals. d. the number of electrons in its outermost shell. e. the distance between the nucleus and the outermost shell electrons. 02. The atoms involved in a __________ covalent bond share these electrons __________, while the atoms involved in a __________ covalent bond share these electrons __________. a. polar, equally, nonpolar, unequally b. nonpolar, equally, polar, unequally c. ionic, unequally, nonpolar, equally d. nonpolar, unequally, ionic, equally e. None of the above is a correct answer. 03. Adenine makes up 40% of the nucleotides in a sample of nuclear DNA from an organism. What percent of the nucleotides in this sample will be thymine? a. 10% b. 20% c. 30% d. 40% e. Percent cannot be determined from the information provided. 04. That a single nucleotide mutation leads to the production of hemoglobin with a single incorrect amino acid is evidence that a. the genetic code is overlapping. b. the genetic code is nonoverlapping. c. many tRNAs can recognize a single codon. d. many codons are recognized by a single tRNA. e. Both b and d are correct answers. 05. Which of the following is the strongest interaction in the cytoplasm of a cell? a. hydrogen bond b. hydrophobic effect c. ionic bond d. peptide bond e. van der Waals interaction

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Questions for Fall 2014 for Bio 286 cell biology at QC.

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  • BIOL 286/586 Exam I October 2014

    Name:____________________________________________________

    Personal Information on the answer sheet

    --Enter your name in the boxes, fill in the corresponding circles --Sign your name at the top

    Test answers on the answer sheet, fill in the BEST possible answer.

    01. The chemical reactivity of an atom is determined by

    a. the total number of neutrons in its nucleus. b. the total number of protons in its nucleus. c. the total number of electrons in its orbitals. d. the number of electrons in its outermost shell. e. the distance between the nucleus and the outermost shell electrons.

    02. The atoms involved in a __________ covalent bond share these electrons __________, while the atoms involved in a __________ covalent bond share these electrons __________.

    a. polar, equally, nonpolar, unequally b. nonpolar, equally, polar, unequally c. ionic, unequally, nonpolar, equally d. nonpolar, unequally, ionic, equally e. None of the above is a correct answer.

    03. Adenine makes up 40% of the nucleotides in a sample of nuclear DNA from an organism. What percent of the nucleotides in this sample will be thymine?

    a. 10% b. 20% c. 30% d. 40% e. Percent cannot be determined from the information provided.

    04. That a single nucleotide mutation leads to the production of hemoglobin with a single incorrect amino acid is evidence that

    a. the genetic code is overlapping. b. the genetic code is nonoverlapping. c. many tRNAs can recognize a single codon. d. many codons are recognized by a single tRNA. e. Both b and d are correct answers.

    05. Which of the following is the strongest interaction in the cytoplasm of a cell?

    a. hydrogen bond b. hydrophobic effect c. ionic bond d. peptide bond e. van der Waals interaction

  • 06. RNA in cells differs from DNA in that a. it contains the base uracil, which pairs with cytosine. b. it is single-stranded and cannot form base pairs. c. it is single-stranded and can fold up into a variety of structures. d. the sugar ribose contains fewer oxygen atoms than does deoxyribose. e. it has a 3 hydroxyl group.

    07. Ribosomes are composed of

    a. two subunits, each consisting of rRNA only. b. two subunits, each consisting of 30-40 proteins only. c. both rRNA and protein. d. mRNA, rRNA, and protein. e. mRNA, tRNA, rRNA, and protein.

    08. The greatest similarities among codons specifying the same amino acid occur a. in the first two nucleotides of the triplet. b. in the last two nucleotides of the triplet. c. in the first and third nucleotides of the triplet. d. in the third nucleotide of the triplet. e. in the middle nucleotide of the triplet.

    09. Which of the following chemical groups is not used to construct a DNA molecule?

    a. five-carbon sugar b. phosphate c. nitrogen-containing base d. six-carbon sugar e. None of the above is a correct answer.

    10. Which of the following molecules of RNA would you predict to be the most likely to fold into a specific structure as a result of intramolecular (within the same molecule) base-pairing?

    a. 5-CCCUAAAAAAAAAAAAAAAAUUUUUUUUUUUUUUUUAGGG-3 b. 5-UGUGUGUGUGUGUGUGUGUGUGUGUGUGUGUGUGUGUGUG-3 c. 5-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-3 d. 5-GGAAAAGGAGAUGGGCAAGGGGAAAAGGAGAUGGGCAAGG-3 e. 5-UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU-3

  • 11. Which of the following statements is FALSE?

    1. A new RNA molecule can begin to be synthesized from a gene before the previous RNA molecules synthesis is completed.

    2. If two genes are to be expressed in a cell, these two genes can be transcribed with different efficiencies.

    3. RNA polymerase and transcription factors are involved in unwinding the DNA helix and catalyzing the formation of the phosphodiester bonds between nucleotides.

    4. Unlike DNA, RNA uses a uracil base and a deoxyribose sugar.

    a. Statement 1 b. Statement 2 c. Statement 3 d. Statement 4 e. Statements 1 and 2

    12. __________ are a macromolecular complexes that associate with pre-mRNA and function to remove introns.

    a. Splicers b. sLURPS c. Spliceosomes d. Splicing bodies e. Splice engines

    13. Triacylglycerol is a. a lipid forming plasma membranes. b. a lipid with at least one phosphate group. c. a lipid made of glycerol and 3 fatty acids. d. a lipid with a characteristic 4 ring structure. e. a lipid with 3 glycerol molecules.

    14. Proteins are often composed of two or more distinct regions that fold up independently of one another. They often represent parts that function in a semi-independent manner. These regions are called

    a. protein pockets. b. functional groups. c. domains. d. consensus sites. e. Both a and c are correct answers.

    15. The clustering of codons in the genetic code tables provides what advantage to living organisms?

    a. Clustering assures that all amino acids are different. b. Clustering ensures that a single base change will often replace a hydrophobic amino acid with another hydrophobic amino acid. c. A single base change will often not change the amino acid that is to be inserted into the growing polypeptides. d. Clustering increases the lifespan of the organism. e. Both b and c are correct answers.

  • 16. You supply a cell with 3H-thymidine (radioactive) for a period of 30 minutes. What has most likely happened during the 30 minute-incubation?

    a. All of the RNA synthesized during this period was radiolabeled. b. All of the DNA synthesized during this period was radiolabeled. c. All of the polysaccharides synthesized during this period were radiolabeled. d. All of the protein synthesized during this period was radiolabeled. e. All of the polyA tails of mRNAs were labeled.

    18. Anticodons are found on a. DNA b. mRNA c. tRNA d. rRNA e. miRNA

    19. In class we discussed the contributions of Henrietta Lacks to our understanding of cell biology. She is famous because

    a. she discovered that bacteriophage infect bacteria with DNA, not protein. b. she discovered that bacteriophage infect bacteria with protein, not DNA. c. a tumor taken from her body was used to form a line of cells used by many biologists. d. she provided the X-ray data used by Watson and Crick to decipher DNA structure. e. she discovered that introns are removed (spliced) from many pre-mRNAs.

    20. If a protein is 300 amino acids long, then there are

    a. 300 nucleotide bases in the DNA gene. b. 300 codons in the mRNA sequence. c. 300 nucleotides in the anticodons. d. 100 nucleotide bases in the messenger RNA. e. 100 anticodons in the tRNA.

    21. The chemical bonds in DNA by which the sugar components of adjacent nucleotides are linked through the phosphate groups are called _________ bonds.

    a. phosphodiester b. hydrogen c. hydrophobic d. glycosidic e. ionic

    22. Clusters of highly repetitive DNA located near the centromeres and telomeres are called

    a. nucleosomes. b. euchromatin. c. chromatids. d. heterochromatin. e. 30 nm chromatin.

    23. In what direction is a polypeptide produced (relative to the polypeptide)?

    a. 3' to 5' direction b. 5' to 3' direction c. N-terminal to C-terminal direction d. C-terminal to N-terminal direction e. N-terminal to 3' direction

  • 24. Of the 64 possible codons, how many do not code for amino acids? a. 20 b. 61 c. 0 d. 3 e. 21

    25. Hydrocarbons are NOT soluble in water because

    a. they are hydrophilic. b. the CH bond is nonpolar. c. they do not ionize. d. they are large molecules. e. they are lighter than water.

    26. The elongation cycle of translation requires the hydrolysis of __________ GTPs.

    a. 1 b. 2 c. 3 d. 4 e. The answer can be either a, b, c or d depending on the indentify of the specific polypeptide.

    27. You treat a purified preparation of a secreted protein with a reagent that breaks bonds between sulfur atoms. Which level(s) of protein structure are likely to be affected?

    a. Tertiary b. Secondary c. Primary d. Quaternary e. Both tertiary and quaternary will be affected.

    28. The subunits of macromolecules are held together by __________bonds, while macromolecular assemblies (such as ribosomes) are held together by __________ bonds.

    a. noncovalent, covalent b. noncovalent, noncovalent c. covalent, covalent d. covalent, noncovalent e. ionic, covalent

    29. RNA a. is always single stranded. b. may function as an enzyme. c. contains the same ribose sugar as DNA. d. unlike DNA, is not a polymer. e. has the same bases as DNA.

    30. Genes in eukaryotic cells often have introns coded for by the DNA. These sequences are ultimately not translated into proteins. Why?

    a. Introns are removed from RNA molecules by the spliceosome, which works in the nucleus. b. Introns are not transcribed by RNA polymerase. c. Introns are removed by catalytic RNAs in the cytoplasm. d. The ribosome will skip over intron sequences when translating RNA into protein. e. None of the above is a correct answer.

  • 31. Ionic bonds result from a(n)

    a. equal sharing of electrons b. unequal sharing of electrons c. a transfer of electrons from one atom to another d. the formation of ions. e. Both c and d are correct answers.

    32. Which of the following is a nucleotide?

    a. phosphate + ribose b. adenine + deoxyribose c. sugar + nitrogenous base d. adenine + ribose + phosphate e. Both b and c are correct answers.

    33. In eukaryotes, __________ is used to transcribe ___________ genes while __________ is used to transcribe __________ genes.

    a. RNA polymerase I, mRNA, RNA polymerase II, tRNA b. RNA polymerase I, tRNA, RNA polymerase II, mRNA c. RNA polymerase II, mRNA, RNA polymerase III, tRNA d. RNA polymerase I, mRNA, RNA polymerase II, rRNA e. RNA polymerase IV, mRNA, RNA polymerase II, rRNA

    34. The assembly of __________ and __________ into ribosomal subunits occurs in the __________.

    a. mRNA, proteins, cytoplasm b. rRNA, lipids, cytoplasm c. rRNA, proteins, cytoplasm d. rRNA, oligosaccharides, nucleus e. rRNA, proteins, nucleus

    35. __________ and __________ are used to process (alter) RNAs in the __________ after transcription.

    a. snoRNA, snRNA, nucleus b. snoRNA, snRNA, cytoplasm c. miRNA, snRNA, nucleus d. miRNA, snRNA, cytoplasm e. miRNA, snRNA, nucleus

    36. The TATA box is a. a protein domain in transcription factors that binds to promoter DNA. b. a protein domain in tRNA synthetase that binds to promoter DNA. c. RNA sequences at intron/exon splice sites. d. DNA sequences at intron/exon splice sites. e. DNA sequences in the promoter region of a gene.

    37. The 5 methylguanosine cap

    a. on tRNAs is linked to an amino acid. b. on rRNAs is crucial to the final ribosome shape. c. aids in mRNA transport from the nucleus. d. aids in mRNA translation in the cytoplasm. e. Both c and d are correct answers.

  • 38. Which of the following has the most glycosidic bonds? a. RNA b. DNA c. glucose d. glycogen e. histone

    39. Which of the following is involved in activating tRNA for translation? a. helicase b. eIF2 c. RNA polymerase d. aminoacyl-tRNA synthetase e. Both b and d are correct answers.

    40. In eukaryotes the initiating AUG is distinguished from subsequent internal AUGs in part by __________

    a. TATA boxes. b. promoter sequences. c. zinc fingers. d. homeodomains. e. Kozak sequences.

    41. Polymers of polysaccharides, nucleic acids, and polypeptides are all synthesized from monomers by

    a. connecting monosaccharides together. b. the addition of water to each monomer. c. the removal of water (condensation synthesis). d. ionic bonding of monomers. e. the formation of disulfide bridges between monomers.

    42. The bonds responsible for the crystalline structure of NaCl are a. nonpolar covalent bonds. b. polar covalent bonds. c. ionic bonds. d. hydrogen bonds. e. hydrophobic interactions.

    43. Polypeptides have _______ and _______ end.

    a. a start; a stop b. a +; a c. an Nterminus; a Cterminus d. a 5; a 3 e. an ; a

    44. Which of the following is a disaccharide?

    a. lactose b. glucose c. fructose d. galactose e. None of the above are disaccharides.

  • 45. Molecular chaperones a. bind to hydrophilic regions of polypeptides. b. assist in the degradation of unfolded proteins. c. help form peptide bonds. d. assist in the transport of proteins outside the cell. e. help proteins to fold properly.

    46. Some common polypeptide _____________ structures are helices and sheets and these are stabilized primarily by _____________ bonds.

    a. tertiary, ionic b. tertiary, van der Waals c. primary, hydrogen d. secondary, hydrogen e. secondary, ionic

    47. Which two functional groups are always found in amino acids?

    a. amino and sulfhydryl b. carbonyl and carboxyl c. carboxyl and amino d. alcohol and aldehyde e. acyl and amino

    48. What word below characterizes the amino acids that are found in an -helical segment of a protein that spans a membrane?

    a. circular b. hydrophilic c. hydrophobic d. antiparallel e. parallel

    For questions 49 and 50 use the following template DNA sequence: 3 AAC GAC TTA GCT TAG 5 49. What would be the sequence of bases on the coding DNA strand?

    a. 5 AAC GAC TTA GCT TAG 3 b. 5 AAC GAC UUA GCU UAG 3 c. 5 UUG CUG AAU CGA AUC 3 d. 5 TTG CTG AAT CGA ATC 3

    50. What would be the sequence of bases on the complimentary mRNA strand? a. 5 AAC GAC TTA GCT TAG 3 b. 5 AAC GAC UUA GCU UAG 3 c. 5 UUG CUG AAU CGA AUC 3 d. 5 TTG CTG AAT CGA ATC 3