1. In yeast signal transduction, the yeast cells A)secrete molecules that result in response by other yeast cells. B)must physically and directly interact. C)produce signal molecules that change themselves so they can interact with one another. D)produce response molecules that diffuse to other yeast cells. E)mate, after which the new cells secrete hybrid signals.

A

2. Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP? A)It would employ a transduction pathway directly from an external messenger. B)It could activate only the epinephrine system. C)It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane. D)It would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane. E)It would be able to carry out reception and transduction but would not be able to respond to a signal.

C

3. Because most receptors are membrane proteins, which of the following is usually true? A)They open and close in response to protein signals. B)They change their conformation after binding with signal polypeptides. C)They are only attached to one membrane surface: exterior or interior. D)They preferentially bind with lipid or glycolipid signal molecules. E)They lead to changes in intracellular ion concentration.

B

4. Since steroid receptors are located intracellularly, which of the following is true? A)The receptor molecules are themselves lipids or glycolipids. B)The steroid/receptor complex can cross the nuclear membrane. C)The receptor molecules are free to move in and out of most organelles. D)The unbound steroid receptors are quickly recycled by lysosomes. E)The concentration of steroid receptors must be relatively high in most cells.

B

5. The receptors for a group of signaling molecules known as growth factors are often A)cyclic AMP. B)ligand-gated ion channels. C)neurotransmitters. D)receptor tyrosine kinases. E)G protein-coupled receptors.

D

6. Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane? A)phosphorylated receptor tyrosine kinase dimer B)ligand-gated ion channel C)G protein-coupled receptor D)intracellular receptor E)receptor tyrosine kinase

B

7. If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of the following is most likely to result? A)activation of a developmental pathway found in the worm but not in humans B)webbing of fingers or toes C)a form of cancer in which there is insufficient apoptosis D)neurodegeneration E)excess skin exfoliation

C

BS 161 Final ExamStudy online at quizlet.com/_dga2s

8. A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following? A)an increase in cytosolic calcium concentration B)an increase in receptor tyrosine kinase activity C)lower cytoplasmic levels of cAMP D)a decrease in G protein activity E)a decrease in transcriptional activity of certain genes

E

9. Which of the following is a correct association? A)GTPase activity and hydrolysis of GTP to GDP B)adenylyl cyclase activity and the conversion of cAMP to AMP C)phosphorylase activity and the catabolism of glucose D)phosphodiesterase activity and the removal of phosphate groups E)kinase activity and the addition of a tyrosine

A

10. An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum? A)tyrosine kinases B)adenylyl cyclase C)serine/threonine kinases D)phosphodiesterase E)phospholipase C

E

11. Which of the following most likely would be an immediate result of growth factor binding to its receptor? A)protein kinase activity B)phosphorylase activity C)GTPase activity D)protein phosphataseE)adenylyl cyclas eactivity

A

12. Barbara McClintock, who achieved fame for discovering that genes could move within genomes, had her meticulous work ignored for nearly four decades, but eventually won the Nobel Prize. Why was her work so distrusted? A)She worked only with maize, which was considered "merely" a plant. B)Geneticists did not want to lose their cherished notions of DNA stability. C)She allowed no one else to duplicate her work. D)The work of women scientists was still not allowed to be published. E)There were too many alternative explanations for transposition.

B

13. Which of the following is a representation of gene density? A)Humans have ~20,000 genes in 2,900 Mb. B)C. elegans has ~20,000 genes. C)Fritillaria has a genome 40 times the size of a human. D)Humans have 27,000 bp in introns. E)Humans have 2,900 Mb per genome.

A

14. If humans have 2,900 Mb, a specific member of the lily family has 120,000 Mb, and a yeast has ~13 Mb, why can't this data allow us to order their evolutionary significance? A)Size is mostly due to "junk" DNA. B)Size does not vary with gene complexity. C)Size does not compare to gene density. D)Size is comparable only within phyla. E)Size matters less than gene density.

B

15. Fragments of DNA have been extracted from the remnants of extinct woolly mammoths, amplified, and sequenced. These can now be used to A)appreciate the reasons why mammoths went extinct. B)introduce into relatives, such as elephants, certain mammoth traits. C)clone live woolly mammoths. D)study the relationships among woolly mammoths and other wool-producers. E)understand the evolutionary relationships among members of related taxa

E

16. Why is it unwise to try to relate an organism's complexity with its size or number of cells? A)A very large organism may be composed of very few cells or very few cell types. B)A simple organism can have a much larger genome. C)A single-celled organism, such as a bacterium or a protist, still has to conduct all the complex life functions of a large multicellular organism. D)A complex organism can have a very small and simple genome. E)A single-celled organism that is also eukaryotic, such as a yeast, still reproduces mitotically.

C

17. What is metagenomics? A)genomics as applied to an entire phylum B)genomics as applied to a species that most typifies the average phenotype of its genus C)the sequencing of only the most highly conserved genes in a lineage D)sequencing DNA from a group of species from the same ecosystem E)the sequence of one or two representative genes from several species

D

18. Which of the following most correctly describes a shotgun technique for sequencing a genome? A)physical mapping followed immediately by sequencing B)cloning large genome fragments into very large vectors such as YACs, followed by sequencing C)cloning the whole genome directly, from one end to the other D)cloning several sizes of fragments into various size vectors, ordering the clones, and then sequencing them E)genetic mapping followed immediately by sequencing

D

19. What is the difference between a linkage map and a physical map? A)For a physical map, the ATCG order and sequence must be achieved; however, it does not for the linkage map. B)For a linkage map, it is shown how each gene is linked to every other gene. C)For a physical map, the distances must be calculable in units such as nanometers. D)For a linkage map, markers are spaced by recombination frequency, whereas for a physical map they are spaced by numbers of base pairs (bp). E)There is no difference between the two except in the type of pictorial representation.

D

20. In large scale, genome-wide association studies in humans, correlation is sought between A)single nucleotide polymorphisms found in families with a particular introns sequence. B)lengthy sequences that might be shared by most members of a population. C)large inversions that displace the centromere. D)single nucleotide polymorphisms found only in persons with a particular disorder. E)single nucleotide polymorphisms in two or more adjacent genes.

D

21. Which of the following modifications is least likely to alter the rate at which a DNA fragment moves through a gel during electrophoresis? A)methylating the cytosine bases within the DNA fragment B)altering the nucleotide sequence of the DNA fragment C)increasing the length of the DNA fragment D)neutralizing the negative charges within the DNA fragment E)decreasing the length of the DNA fragment

B

22. Pax-6 is a gene that is involved in eye formation in many invertebrates, such as Drosophila. Pax-6 is found as well in vertebrates. A Pax-6 gene from a mouse can be expressed in a fly and the protein (PAX-6) leads to a compound fly eye. This information suggests which of the following? A)PAX-6 proteins have identical amino acid sequences. B)Pax-6 genes are identical in nucleotide sequence. C)Pax-6 is highly conserved and shows shared evolutionary ancestry. D)PAX-6 from a mouse can function in a fly, but a fly's Pax-6 gene cannot function in a mouse. E)PAX6 proteins are different for formation of different kinds of eyes.

C

23. The major advantage of using artificial chromosomes such as YACs and BACs for cloning genes is that A)only one copy of a plasmid can be present in any given cell, whereas many copies of a YAC or BAC can coexist in a single cell. B)plasmids are unable to replicate in cells. C)YACs and BACs can carry much larger DNA fragments than ordinary plasmids can. D)YACs and BACs can be used to express proteins encoded by inserted genes, but plasmids cannot. E)All of these are correct.

C

24. A student wishes to clone a sequence of DNA of ~200 kb. Which vector would be appropriate? A)a BAC B)a plant virus C)a typical bacteriophage D)a large polypeptide E)a plasmid

A

25. The DNA fragments making up a genomic library are generally contained in A)BACs. B)recombinant viral RNA. C)radioactive eukaryotic cells. D)DNA-RNA hybrids. E)individual wells.

A

26. A gene that contains introns can be made shorter (but remain functional) for genetic engineering purposes by using A)a restriction enzyme to cut the gene into shorter pieces. B)DNA ligase to put together fragments of the DNA that code for a particular polypeptide. C)reverse transcriptase to reconstruct the gene from its mRNA. D)RNA polymerase to transcribe the gene. E)DNA polymerase to reconstruct the gene from its polypeptide product.

C

27. In a cell-free system, what other components would you have to provide for this virus to express its genes? A)ribosomes, tRNAs, amino acids, and GTP B)bean cell enzymes C)RNA nucleotides and GTP D)RNA nucleotides, RNA polymerase, and GTP E)ribosomes, tRNAs and amino acids

A

28. To cause a human pandemic, the H5N1 avian flu virus would have to A)develop into a virus with a different host range. B)become capable of human-to-human transmission. C)spread to primates such as chimpanzees. D)become much more pathogenic. E)arise independently in chickens in North and South America.

B

29. In the figure, at the arrow marked II (pointing at viral DNA before its being reproduced), what enzyme(s) are beingutilized? A)host cell RNA polymerase B)viral DNA polymerase C)host cell DNA and RNA polymerases D)reverse transcriptase E)host cell DNA polymerase

E

30. Most molecular biologists think that viruses originated from fragments of cellular nucleic acid. Which of the following observations supports this theory? A)Viruses are enclosed in protein capsids rather than plasma membranes. B)Viral genomes are usually similar to the genome of the host cell. C)Viruses can infect both prokaryotic and eukaryotic cells. D)Viruses contain either DNA or RNA. E)Viruses can reproduce only inside host cells.

B

31. Why do RNA viruses appear to have higher rates of mutation? A)RNA viruses can incorporate a variety of nonstandard bases. B)RNA viruses replicate faster. C)Replication of their genomes does not involve proofreading. D)RNA nucleotides are more unstable than DNA E)RNA viruses are more sensitive to mutagens.

C

32. Most human-infecting viruses are maintained in the human population only. However, a zoonosis is a disease that is transmitted from other vertebrates to humans, at least sporadically, without requiring viral mutation. Which of the following is the best example of a zoonosis? A)HIV B)rabies C)smallpox D)hepatitis virus E)herpesvirus

B

33. By which of the following processes is insulin synthesized? A) transcription B) hydrolysis C) translation D) decarboxylation E) phosphorylation

C

34. The subunits of insulin are A) monosaccharides B) nucleotides C) fatty acids D) amino acids E) phospholipids

D

35. Following synthesis, the insulin polypeptide undergoes disulfide bond formation. This is an example of a ______________ that affects _____________. A) posttranslational process; primary structure B) posttranslational process; tertiary structure C) transcriptional process; primary structure D) posttranscriptional process; tertiary structure

B

36. As a secreted protein, the route traveled by insulin to the outside of the pancreatic cells is A) rough ER → Golgi → plasma membrane B) Golgi → rough ER → plasma membrane C) Golgi → lysosomes → plasma membrane D) Golgi → smooth ER → plasma membrane E) rough ER → Golgi → lysosomes

A

37. The hormone epinephrine (also called adrenaline) is secreted from cells of the adrenal gland in response to athreatening or exciting condition. The hormone binds to G protein-coupled receptors on the plasma membrane of liver cells, stimulatingthe breakdown of glycogen, a polymer of glucose. The glucose diffuses out of the liver cells, is circulated in the bloodstream, and issubsequently taken up into muscle cells, where it is used in respiration. The ATP produced by respiration is used for muscle contraction,allowing the organism to run for safety in response to the threat. Use all of this information to answer the following four questions. 8) Once epinephrine binds to the liver cells, the signal transduction pathway occurs in the order epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → cAMP. Which of the following is the second messenger? A) G protein-coupled receptor B) G protein C) GTP D) adenylyl cyclase E) cAMP

E

38. The hormone epinephrine (also called adrenaline) is secreted from cells of the adrenal gland in response to athreatening or exciting condition. The hormone binds to G protein-coupled receptors on the plasma membrane of liver cells, stimulatingthe breakdown of glycogen, a polymer of glucose. The glucose diffuses out of the liver cells, is circulated in the bloodstream, and issubsequently taken up into muscle cells, where it is used in respiration. The ATP produced by respiration is used for muscle contraction,allowing the organism to run for safety in response to the threat. Use all of this information to answer the following fourquestions.Glycogen is a __________ and is broken down to glucose by _________. A) polypeptide; dehydration B) protein; translation C) polysaccharide; hydrolysis D) lipid; decarboxylation E) nucleic acid; denaturation

C

39. The hormone epinephrine (also called adrenaline) is secreted from cells of the adrenal gland in response to athreatening or exciting condition. The hormone binds to G protein-coupled receptors on the plasma membrane of liver cells, stimulatingthe breakdown of glycogen, a polymer of glucose. The glucose diffuses out of the liver cells, is circulated in the bloodstream, and issubsequently taken up into muscle cells, where it is used in respiration. The ATP produced by respiration is used for muscle contraction,allowing the organism to run for safety in response to the threat. Use all of this information to answer the following four questions.Which of the following regarding glucose export from the liver cells into the bloodstream is true? A) It requires a membrane protein B) It occurs by osmosis C) It requires energy D) It occurs by active transportE) It is endergonic

A

40. The hormone epinephrine (also called adrenaline) is secreted from cells of the adrenal gland in response to athreatening or exciting condition. The hormone binds to G protein-coupled receptors on the plasma membrane of liver cells, stimulatingthe breakdown of glycogen, a polymer of glucose. The glucose diffuses out of the liver cells, is circulated in the bloodstream, and issubsequently taken up into muscle cells, where it is used in respiration. The ATP produced by respiration is used for muscle contraction,allowing the organism to run for safety in response to the threat. Use all of this information to answer the following four questions.Following glucose uptake from the bloodstream, the muscele cells generate the ATP needed for muscle contraction through the process of respiration, which __________ glucose to ___________. A) oxidizes ... O2 B) oxidizes ... NADH C) reduces ... CO2 D) oxidizes ... CO2 E) reduces ... NADH

D

41. Based on the polarity of water molecules, the solute above is most likely A)hydrophobic. B)nonpolar. C)uncharged. D)a cation. E)an anion

D

42. what is a hydroxyl group? -OH

43. Which of the following hydrocarbons has a double bond in its carbon skeleton? A)C2H4 B)C3H8 C)CH4 D)C2H6 E)C2H2

A

44. Answers may be used once, more than once, or not at all. A. applies to nucleic acids B. applies to proteins C. applies to polysaccharides D. applies to lipids E. applies to all macromolecules 4)synthesis involves dehydration reactions

E

45. Answers may be used once, more than once, or not at all.A. applies to nucleic acids B. applies to proteins C. applies to polysaccharides D. applies to lipids E. applies to all macromolecules5)monomers are linked in peptide bonds

B

46. What is a functional group on it side chain that is likely to be ionized at the pH of the cell? A

47. What is a functional group on it side chain that can contribute to tertiary structure by forming a coavlent bond? D

48. Which of the following occurs by hydrolysis? A)the breakdown of polypeptides to monosaccharides B)the synthesis of polysaccharides from monosaccharides C)the breakdown of nucleic acids to nucleotides D)the formation of peptide bonds E)the addition of a fatty acid to glycerol

C

49. Which of the following involves the formation of hydrogen bonds? A)disulfide bridge formation in proteins B)α-helix formation in proteins C)interaction between carboxyl and amino groups in side chains of proteins D)interaction between fatty acid tails in phospholipid bilayers E)the attachment of an amino acid to a growing polypeptide chain

B

50. Two DNA molecules have the following base pair compositions: A. ATGGTAA B. GGAACCC TACCATT CCTTGGG Which one would have to be heated to a higher temperature to completely separate the two strands? A) A B) B C) Neither; they would be completely separated at the same temperature

B

51. Which of the following best describes the flow of genetic information in a eukaryotic cell? A)transcription in the nucleus → transport of mRNA to the cytosol → translation on ribosomes B)transport of mRNA to the cytosol → translation on ribosomes → transcription in the nucleus C)transport of mRNA to the cytosol → transcription in the nucleus → translation on ribosomes D)translation on ribosomes → transport of mRNA to the cytosol → transcription in the nucleus E)transcription in the nucleus → translation on ribosomes → transport of mRNA to the cytosol

A

52. An enzyme is composed of two identical polypeptides that associate to form the active site. If a mutation occurs that prevents the two polypeptides from associating, what is the most likely outcome? A)the enzyme's primary structure will be unaffected B)the enzyme will no longer have any primary structure C)the enzyme will no longer have any tertiary structure D)the enzyme will no longer bind its substrate

D

53. In which of the following cells would you expect to observe a predominance of free ribosomes? A)a cell that is secreting proteins B)a cell that is producing cytoplasmic enzymes C)a cell that is constructing its extracellular matrix D)a cell that is digesting food particles E)a cell that is enlarging its central vacuole

B

54. Choose the most inclusive category. Each answer may be used once, more than once, or not at all. A. unique to prokaryotic cells B. unique to animal cells C. unique to plant cells D. a feature of all eukaryotic cells E. a feature of all cells plasma membrane

E

55. Choose the most inclusive category. Each answer may be used once, more than once, or not at all. A. unique to prokaryotic cells B. unique to animal cells C. unique to plant cells D. a feature of all eukaryotic cells E. a feature of all cells chloroplasts

C

56. Choose the most inclusive category. Each answer may be used once, more than once, or not at all. A. unique to prokaryotic cells B. unique to animal cells C. unique to plant cells D. a feature of all eukaryotic cells E. a feature of all cells endomembrane system

D

57. All of the following are components of prokaryotic cells except A)DNA. B)cell wall. C)plasma membrane. D)ribosomes. E)mitochondria

E

58. All of the following are common to mitochondria and chloroplasts except A)they both evolved from prokaryotes by endosymbiosis. B)they are both surrounded by single membranes. C)they both contain ribosomes. D)they both contain DNA. E)they are both found in plant cells

B

59. Which of the following best describes the route for transport of a secreted protein, such as insulin? A)Golgi → rough ER → vesicles that fuse with lysosomes B)Golgi → rough ER → vesicles that fuse with the plasma membrane C)rough ER → Golgi → vesicles that fuse with the plasma membrane D)rough ER → Golgi → vesicles that fuse with lysosomes E)smooth ER → Golgi → vesicles that fuse with the plasma membrane

C

60. An enzyme that breaks down nucleic acids resides in the lysosomes of an animal cell. Which of the following statements is incorrect about this enzyme? A)It may participate in phagocytosis B)It may participate in autophagy C)It carries out dehydration reactions D)It could be glycosylated E)Its likely route of transport is rough ER → Golgi → vesicles that fuse with lysosomes

C

61. Each answer may be used one, more than one, or not at all. A. Microtubules B. Microfilaments C. Intermediate filaments D. All of the above Plays a role in maintaining cell shape

D

62. Each answer may be used one, more than one, or not at all. A. Microtubules B. Microfilaments C. Intermediate filaments D. All of the above Key components of flagella in sperm cells

A

63. Each answer may be used one, more than one, or not at all. A. Microtubules B. Microfilaments C. Intermediate filaments D. All of the above Separates chromosomes in eukaryotic cells

A

64. Each answer may be used one, more than one, or not at all. A. Microtubules B. Microfilaments C. Intermediate filaments D. All of the above Composed of actin subunits

B

65. Plasmodesmata in plant cells are most similar in function to which of the followingstructures in animal cells? A)peroxisomes B)desmosomes C)gap junctions D)lysosomes E)tight junctions

C

66. Answers may be used once, more than once, or not at all. A. primary structure B. secondary structure C. tertiary structure D. quaternary structure 27)The level of structure least affected by high temperature

A

67. Answers may be used once, more than once, or not at all. A. primary structure B. secondary structure C. tertiary structure D. quaternary structure 28)The level of structure referring to the interaction between multiple polypeptidechains

D

68. How to know whether something is amphipathic? polar, hydrophilic (water loving),lipophilic (lipid loving)

69. You extract and analyze the membrane lipids from two species of fish, a kingsalmon from the cold arctic waters of Alaska and a barracuda from the warm tropical waters of the Carribbean. Themembranes in both organisms are composed primarily of the two moleucules shown above, but molecule A is in lowerabundance in one species. Which species is likely to have the lower percentage of molecule A in its membranes (Bentfatty acid chain)A)the barracuda B)the salmon

A

70. Which of the statements below is incorrect regarding the molecules above (one witha bent chain and straight, one with both straight)? A)Both molecules are amphipathic B)Both molecules are phospholipids C)Both molecules are found in biological membranes D)Both molecules could form a bilayer if added to water E)Both molecules have an unsaturated fatty acid tail

E

71. A patient has had an accident and lost a lot of blood. In an attempt to replenish bodyfluids, a paramedic accidentally injects a large amount of concentrated salt solution directly into the patient's veins,causing an increase in the solute concentration of the fluid surrounding the red blood cells. What is the likelyoutcome of this treatment? A)the body fluids will be hypotonic relative to the red blood cells and the cells willshrivel B)the body fluids will be hypotonic relative to the red blood cells and the cells willburst C)the body fluids will be hypertonic relative to the red blood cells and the cells willshrivel D)the body fluids will be hypertonic relative to the red blood cells and the cells willburst E)the body fluids and red blood cells will be isotonic and the cells will shrivel

C

72. In an integral membrane protein which amino acid is least likely to be found in the loop region?

most hydrophillic, since hydrophobictails are inside membrane

73. The net movement of glucose across a biological membrane from higherconcentration to lower concentration occurs by A)osmosis B)phagocytosis C)active transport D)facilitated diffusion E)simple diffusion

D

74. The movement of protons from outside to inside the cell occurs by (sucrose-H+transporter)A)active transport B)simple diffusion C)facilitated diffusion

C

75. The most direct source of energy for the transport of sucrose across the membraneis A)ATP hydrolysis B)the sucrose concentration gradient C)the proton electrochemical gradient

C

76. Which of the following is exergonic? A)Formation of a glycosidic linkage between two monosaccharides B)Addition of an amino acid to a growing polypeptide chain C)Transport of potassium ions against their electrochemical gradient D)Hydrolysis of ATP by a motor protein E)Synthesis of ATP from ADP and inorganic phosphate

D

77. Which of the following is an anabolic process? A)hydrolysis of proteins B)photosynthesis C)respiration D)breakdown of fats E)degradation of glycogen to glucose

B

78. Which of the following statements isnot true of an ATP hydrolysis reaction? A)It is often coupled to the formation of a phosphorylated intermediate. B)It has a positive G C)It is often coupled to a reaction that requires energy D)It is typically catalyzed by an enzyme E)It is exergonic

B

79. A chemical reaction has a G of -6.8 kcal/mol. According to the second law of thermodynamics, which of the following could be coupled to this reaction? A)An endergonic reaction with a G of +4.2 kcal/mol B)An exergonic reaction with a G of -5.0 kcal/mol C)An endergonic reaction with a G of +7.3 kcal/mol D)An exergonic reaction with a G of -7.3 kcal/mol E)Any reaction with a positive G

A

80. In animal cells, hydrolytic enzymes in lysosomes funciton in the degradation of macromolecules and worn-outcellular components, allowing recycing of cellular building blocks. Lysosomes are acidic because protons are activelytransported from the cyotosl into lysosomes. Use this information to answer the nextthree qeustions about lysosomes. 5)What is the most likely route for delivery of the hydrolytic enzymes to the lysosomes? A)rough ER Golgi vesicles that fuse with lysosomes B)Golgi rough ER vesicles that fuse with lysosomes C)cytosol Golgi vesicles that fuse with lysosomes D)cytosol central vacuole vesicles that fuse with lysosomes E)rough ER central vacuole vesicles that fuse with lysosomes

A

81. In animal cells, hydrolytic enzymes in lysosomes funciton in the degradation of macromolecules and worn-outcellular components, allowing recycing of cellular building blocks. Lysosomes are acidic because protons are activelytransported from the cyotosl into lysosomes. Use this information to answer the nextthree qeustions about lysosomes. 6)Which of the curves below represents the most likely profile for most lysosomal enzymes ? A) Rate of reaction highest at pH 4-5B) Rate of reaction highest at pH 7-8

A

82. In animal cells, hydrolytic enzymes in lysosomes funciton in the degradation of macromolecules and worn-outcellular components, allowing recycing of cellular building blocks. Lysosomes are acidic because protons are activelytransported from the cyotosl into lysosomes. Use this information to answer the nextthree qeustions about lysosomes. Which of following would apply to the import of protons to the lysosomes? A)It is catabolic B)It is endergonic C)It is spontaneous D)It releases energy E)Protons are being transported down their electrochemical gradient

B

83. A chemical reaction A + B C + D is proceeding spontaneously towards the formation of A + B. Based on this information, which of the following statements isincorrect? A)The formation of A + B (reverse reaction) moves the reaction towards equilibrium B)The forward reaction has a positive G C)The reverse reaction has a negative G D)The forward reaction requires energy E)The reverse reaction is endergonic

E

84. For the chemical reaction A + B C + D, G = 0. Based on this information, which of the following statements is incorrect? A)The formation of more C + D would move the reaction away from equilibrium. B)The reaction is proceeding spontaneously towards the formation of more C + D. C)The formation of more A + B would move the reaction away from equilibrium. D)The formation of more A + B would require energy. E)The formation of more C + D would require energy.

B

85. How might severe fever affect enzymes in your body if the fever is not controlled? A)Amino acid side chains in your enzymes may be degraded B)The primary structure of your enzymes may be altered C)Peptide bonds in your enzymes may be hydrolzyed D)The tertiary structure of your enzymes may be altered E)The nucleotide sequence of genes coding for your enzymes may be altered

D

86. Which curve(s) on the graphs are most likely to represent the temperature and pH profiles of an enzyme taken froma bacterium that lives in a mildly alkaline hot springs at temperatures of 70°C or higher? A)curves 1 (RoR peak at 40 C) and 5 (RoR peak at pH 8)B)curves 2 (RoR peak at 55 C) and 4 (RoR peak at pH 2)C)curves 3 (RoR peak at 80 C) and 4 (RoR peak at pH 2)D)curves 2 (RoR peak at 55 C) and 5 (RoR peak at pH 8)E)curves 3 (RoR peak at 80 C) and 5 (RoR peak at pH 8)

E

87. During respiration, the carbon atoms in glucose ultimately wind up in A)ATP B)C6H12O6 C)NADH D)NADPH E)CO2

E

88. A. photosynthesis B. respiration C. both D.neither Answers may be used once, more than once, or not at all. 13)Oxidizes CO2

D

89. A. photosynthesis B. respiration C. both D.neither Answers may be used once, more than once, or not at all. 14)Generates ATP by chemiosmosis

C

90. A. photosynthesis B. respiration C. both D.neither Answers may be used once, more than once, or not at all. 15)Results in the transfer of electrons from water to sugar

A

91. Which of the following statements concerning the breakdown of glucose to CO2 and water during repsirationisincorrect? A)It is catabolic B)It releases energy, some of which is recaptured in ATP C)It occurs in many small steps, decreasing the amount of energy lost as heat and increasing the amount of energy available for ATP synthesis D)It results in the transfer of electrons from more electronegative atoms in glucose to less electronegative oxygen E)It is exergonic

D

92. A. cytosol B. chloroplast inner membrane C. thylakoid membrane D. thylakoid space E. stroma 17)Site of glycolysis in plants

A

93. A. cytosol B. chloroplast inner membrane C. thylakoid membrane D. thylakoid space E. stroma 18)Accumulation of protons in this location powers photophosphorylation of ADP

D

94. A. cytosol B. chloroplast inner membrane C. thylakoid membrane D. thylakoid space E. stroma 19)The pH of this compartment increases in the light

E

95. Hexokinase catalyzes the first step in glycolysis. What is the most likely site of hexokinase synthesis? A)Ribosomes on the rough ER B)Ribosomes in the cytosol C)Ribosomes in the mitochondrion D)Ribosomes in the nucleus E)Ribosomes in the chloroplast

B

96. 6 CO2+ 6H2O+ Energy C6H12O6 + 6O2 21)What does the forward reaction represent? A)The summary reaction for the Calvin cycle. B)The summary reaction for the citric acid cycle. C)The summary reaction for fermentation. D)The summary reaction for photosynthesis. E)The summary reaction for respiration.

D

97. 6 CO2+ 6H2O+ Energy C6H12O6 + 6O2Which of the following statements describes the reverse reaction? A)CO2 is reduced andH2O is oxidized. B)O2 is oxidized andH2O is reduced. C)C6H12O6 is oxidized andO2 is reduced. D)C6H12O6 is reduced andCO2 is oxidized. E)C6H12O6 is reduced andO2 is oxidized.

C

98. choose from the list below. A. glycolysis B. conversion of pyruvate to acetyl CoA C. citric acid cycle D. oxidative phosphorylation 23)produces most of the ATP during respiration

D

99. choose from the list below. A. glycolysis B. conversion of pyruvate to acetyl CoA C. citric acid cycle D. oxidative phosphorylation 24)stage of respiration that releases most of the CO2

C

100. Which of the following best summarizes the flow of electrons during respriation? A)glucose --> NADH --> electron transport chain --> proton gradient --> CO2 B)glucose --> CO2 --> electron transport chain --> ATP --> NADH C)glucose --> NADH --> electron transport chain --> proton gradient --> ATP D)glucose --> NADH --> electron transport chain --> O2 E)glucose --> electron transport chain --> NADH --> O2

D

101. Which of the following statements iscorrect concerning the reaction: C4H6O5 + NAD+ C4H4O5 + NADH + H+ A)NAD+ is reduced and C4H6O5 is oxidized B)C4H6O5 is reduced and NAD+ is oxidized C)NADH is reduced and NAD+ is oxidized D)C4H6O5 is reduced and NADH is oxidized E)C4H6O5 is oxidized and NADH is reduced

A

102. The following coupled reaction occurs during glycolysis and is catalyzed by the enzyme pyruvate kinase: (Phosphoenolpyruvate (CH2C2O3P-) + ADP --> ATP + Pyruvate(CH3C2O3-)Which of the following statements regarding this reaction is incorrect?A)It occurs in the cytosol B)It results in a substrate-level phosphorylation C)Phosphoenolpyruvate is a substrate of pyruvate kinase D)ADP binds to the active site of pyruvate kinase E)Pyruvate kinase is consumed by the reaction

E

103. In the citric acid cycle, citrate, a 6-carbon compound, loses a CO2, resulting in the formation of a 5-carboncompound. This is an example of which type of reaction? A)decarboxylation B)phosphorylation C)dephosphorylation D)isomerization

A

104. Which of the following can continue in the absence ofO2? A)glycolysis B)conversion of pyruvate to acetyl CoA C)citric acid cycle D)generation of the proton gradient E)oxidative phosphorylation

A

105. What is the primary function of the Calvin cycle? A)to synthesize sugar from CO2 B)to oxidize glucose to CO2 C)to transfer electrons from water to O2 D)to use NADPH to release CO2 E)to synthesize ATP

A

106. Which of the following statements best represents the relationship between the light reactions of photosynthesisand the Calvin cycle? A)The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. B)The light reactions provide ATP and NADPH to the Calvin cycle, and the Calvin cycle returns ADP, Pi, and NADP+to the light reactions. C)The light reactions provide ADP, Pi, and NADP+ to the Calvin cycle, and the Calvin cycle returns ATP and NADPHto the light reactions. D)The light reactions provide the Calvin cycle with oxygen, and the Calvin cycle provides the light reactions with water to split. E)The light reactions provide ATP and NADPH to the Calvin cycle, and the Calvin cycle provides water and electronsto the light reactions.

B

107. What is the maximum number of moles of hexose that could be produced from the fixation of six moles of CO2during photosynthesis? A)1 B)6 C)12 D)18 E)38

A

108. In mitochondria, chemiosmosis results in the passive transport of protons from the matrix into theintermembrane space, whereas in chloroplasts, chemiosmosis results in the passive transport of protons from A)the stroma to photosystem II B)the stroma to the thylakoid space C)the thylakoid space to the stroma D)the intermembrane space to the stroma E)the stroma to the intermembrane space

C

109. Answers may be used once, more than once, or not at all A. occurs only during oxidative phosphorylation B. occurs only during photophosphorylation C. occurs during both oxidative phosphorylation and photophosphorylation D. occurs during neither oxidative phosphorylation nor photophosphorylation 34)ATP is synthesized by an ATP synthase

C

110. Answers may be used once, more than once, or not at all A. occurs only during oxidative phosphorylation B. occurs only during photophosphorylation C. occurs during both oxidative phosphorylation and photophosphorylation D. occurs during neither oxidative phosphorylation nor photophosphorylation 35)Facilitated diffusion of protons provides the direct source of energy for ATP synthesis from ADP and inorganicphosphate

C

111. The enzyme Rubisco catalyzes the first step in the Calvin cycle. Which of the following statements about Rubisco is incorrect ? A)It does not alter G of the reaction it catalyzes. B)It is a protein. C)One of its substrates is CO2. D)It is located in the thylakoid space. E)It catalyzes a carboxylation reaction.

D

112. Green light is least effective for driving photosynthesis because A)photons in the green part of the visible spectrum are absorbed most effectively by chlorophyll. B)photons in the green part of the visible spectrum have less energy than those in the red part of the spectrum. C)photons in the green part of the visible spectrum have more energy than those in the red part of the spectrum. D)photons in the green part of the visible spectrum are absorbed least effectively by chlorophyll. E)Green light is actually the most effective for photosynthesis.

D

113. Which of the following doesnot occur in the Calvin cycle? A)synthesis of a 3-carbon sugar phosphate B)synthesis of ATP C)fixation of CO2 D)hydrolysis of ATP E)oxidation of NADPH

B

114. An oak seedling grows into a tree. In this context, which of the following statements isincorrect? A)Most of the ATP needed for growth was produced by respiration in the mitochondria. B)The increased mass came primarily from organic material in the soil. C)The increased mass came primarily from CO2 in the air. D)Some of the sugar produced by photosynthesis in the leaves provided carbon skeletons needed for the synthesisof macromolecules during growth. E)Some of the sugar produced by photosynthesis in the leaves was converted to a form that could be exported andused for growth of the tree's root system.

B

115. Which of the following statements best summarizes the cycling of O2 through the ecosystem? A)O2 in the atmosphere is produced by photosynthesis and consumed by respiration B)O2 in the atmosphere is produced by respiration and consumed by photosynthesis C)O2 in the atmosphere is produced by the oxidation of CO2 D)O2 in the atmosphere is consumed by the oxidation of CO2

A

116. Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? A)centrioles and centromeres B)Golgi-derived vesicles C)cyclin-dependent kinases D)actin and myosin E)kinetochores

B

117. Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? A)Chromosomally abnormal cells still have normal metabolism. B)Transformation introduces new chromosomes into cells. C)Cancer cells are no longer density dependent. D)Cancer cells are no longer anchorage dependent. E)Chromosomally abnormal cells can still go through cell cycle checkpoints.

E

118. What do gap genes, pair-rule genes, segment polarity genes, and homeotic genes all have in common? A)Their products act as transcription factors. B)They have no counterparts in animals other than Drosophila. C)Their products are all synthesized prior to fertilization. D)They act independently of other positional information. E)They apparently can be activated and inactivated at any time of the fly's life.

A

119. Genomic imprinting, DNA methylation, and histone acetylation are all examples of A)epigenetic phenomena. B)genetic mutation. C)karyotypes. D)translocation. E)chromosomal rearrangements.

A

120. There is a mutation in the repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of these would characterize such a mutant? A)It cannot bind to the operator. B)It makes a repressor that binds CAP. C)It makes molecules that bind to one another. D)It cannot bind to the inducer. E)It cannot make a functional repressor.

D

121. The tRNA shown in the figure has its 3' end projecting beyond its 5' end. What will occur at this 3' end? A)The codon and anticodon complement one another. B)The amino acid binds covalently. C)The 5' cap of the mRNA will become covalently bound. D)The small and large subunits of the ribosome will attach to it. E)The excess nucleotides (ACCA) will be cleaved off at the ribosome.

B

122. A lack of which molecule would result in the cell's inability to "turn off" genes? A)ubiquitin B)operon C)promoter D)corepressor E)inducer

D

123. Which of the following is a protein produced by a regulatory gene? A)promoter B)operon C)corepressor D)repressor E)inducer

D

124. The role of a metabolite that controls a repressible operon is to A)increase the production of inactive repressor proteins. B)bind to the promoter region and decrease the affinity of RNA polymerase for the promoter. C)bind to the operator region and block the attachment of RNA polymerase to the promoter. D)bind to the repressor protein and inactivate it. E)bind to the repressor protein and activate it.

E

125. Which small-scale mutation would be most likely to have a catastrophic effect on the functioning of a protein? A)a base deletion near the start of a gene B)a base deletion near the end of the coding sequence, but not in the terminator codon C)deletion of three bases near the start of the coding sequence, but not in the initiator codon D)a base substitution E)a base insertion near the end of the coding sequence, but not in the terminator codon

A

126. What is the effect of a nonsense mutation in a gene? A)It changes an amino acid in the encoded protein. B)It has no effect on the amino acid sequence of the encoded protein. C)It alters the reading frame of the mRNA. D)It introduces a premature stop codon into the mRNA. E)It prevents introns from being excised.

D

127. When the ribosome reaches a stop codon on the mRNA, no corresponding tRNA enters the A site. If the translation reaction were to be experimentally stopped at this point, which of the following would you be able to isolate? A)separated ribosomal subunits, a polypeptide, and free tRNA B)separated ribosomal subunits with a polypeptide attached to the tRNA C)an assembled ribosome with a polypeptide attached to the tRNA in the P site D)a cell with fewer ribosomes E)an assembled ribosome with a separated polypeptide

C

128. Which of the following is the first event to take place in translation in eukaryotes? A)binding of the larger ribosomal subunit to smaller ribosomal subunits B)covalent bonding between the first two amino acids C)the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA D)base pairing of activated methionine-tRNA to AUG of the messenger RNA E)elongation of the polypeptide

C

129. Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the A)shape of the A and P sites of ribosomes. B)bonding of the anticodon to the codon and the attachment of amino acids to tRNAs. C)attachment of amino acids to tRNAs. D)bonding of the anticodon to the codon. E)binding of ribosomes to mRNA.

B

130. What is a ribozyme? A)an enzyme that synthesizes RNA as part of the transcription process B)an enzyme that catalyzes the association between the large and small ribosomal subunits C)an enzyme that synthesizes RNA primers during DNA replication D)an RNA with enzymatic activity E)an enzyme that uses RNA as a substrate

D

131. Which of the following statements best describes the termination of transcription in prokaryotes? A)RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA. B)RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase. C)Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome. D)RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript. E)RNA polymerase transcribes through an intron, and the snRNPs cause the polymerase to let go of the transcript.

D

132. Which of the following nucleotide triplets best represents a codon? A)a triplet separated spatially from other triplets B)a triplet in the same reading frame as an upstream AUG C)a triplet that has no corresponding amino acid D)a triplet at the opposite end of tRNA from the attachment site of the amino acid E)a sequence in tRNA at the 3' end

B

133. A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is A)5' TCA 3'. B)3' UGA 5'. C)3' ACU 5'. D)3' UCA 5'. E)either UCA or TCA, depending on wobble in the first base.

D

134. Which of the following statements describes the eukaryotic chromosome? A)The nucleosome is its most basic functional subunit. B)It consists of a single linear molecule of double-stranded DNA plus proteins. C)The number of genes on each chromosome is different in different cell types of an organism. D)It is composed of DNA alone. E)Active transcription occurs on heterochromatin but not euchromatin.

B

135. What is the role of DNA ligase in the elongation of the lagging strand during DNA replication? A)It unwinds the parental double helix. B)It synthesizes RNA nucleotides to make a primer. C)It joins Okazaki fragments together. D)It stabilizes the unwound parental DNA. E)It catalyzes the lengthening of telomeres.

C

136. To repair a thymine dimer by nucleotide excision repair, in which order do the necessary enzymes act? A)helicase, DNA polymerase I, DNA ligase B)endonuclease, DNA polymerase I, DNA ligase C)DNA ligase, nuclease, helicase D)DNA polymerase I, DNA polymerase III, DNA ligase E)exonuclease, DNA polymerase III, RNA primase

B

137. In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin. Which of the following would you expect as a result of this mutation? A)Replication will require a DNA template from another source. B)No replication fork will be formed. C)Replication will occur via RNA polymerase alone. D)No proofreading will occur. E)The DNA will supercoil.

B

138. An Okazaki fragment has which of the following arrangements? A)3' RNA nucleotides, DNA nucleotides 5' B)5' RNA nucleotides, DNA nucleotides 3' C)DNA polymerase I, DNA polymerase III D)primase, polymerase, ligase E)5' DNA to 3'

B

139. Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base? A)DNA in both daughter cells would be radioactive. B)Radioactive thymine would pair with nonradioactive guanine. C)Neither of the two daughter cells would be radioactive. D)One of the daughter cells, but not the other, would have radioactive DNA. E)All four bases of the DNA would be radioactive.

A

140. The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B? A)spindle formation B)cell elongation during anaphase C)DNA synthesis D)spindle attachment to kinetochores E)cleavage furrow formation and cytokinesis

E

141. Which of the following describes the function of an enzyme known as Dicer? A)It chops up single-stranded DNAs from infecting viruses. B)It degrades single-stranded DNA. C)It trims small double-stranded RNAs into molecules that can block translation. D)It degrades single-stranded mRNA. E)It degrades mRNA with no poly-A tail.26)

C

142. During DNA replication, A)all methylation of the DNA is lost at the first round of replication. B)methylation of the DNA is maintained because DNA polymerase directly incorporates methylated nucleotides into the new strand opposite any methylated nucleotides in the template. C)methylated DNA is copied in the cytoplasm, and unmethylated DNA is copied in the nucleus. D)DNA polymerase is blocked by methyl groups, and methylated regions of the genome are therefore left uncopied. E)methylation of the DNA is maintained because methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication

E

143. A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in A)irreversible binding of the repressor to the operator. B)continuous transcription of the structural gene controlled by that regulator. C)inactivation of RNA polymerase by alteration of its active site. D)continuous translation of the mRNA because of alteration of its structure. E)complete inhibition of transcription of the structural gene controlled by that regulator.

B

144. Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product? A)a substitution of the first nucleotide of a GGG codon B)an insertion of a codon C)a deletion of a codon D)a deletion of two nucleotides E)a substitution of the third nucleotide in an ACC codon

D

145. The chromosomes are under tension in metaphase. What allows their migration to the poles duringanaphase?A. the cohesin complexB. the anaphase promoting complex is activatedC. separase is inhibited by securinD. all of the above

B

146. Experiment: Kineticore microtubule is marked prior to anaphase. When the chromosomes pull apart,the mark moves toward the equator. Does this evidence support the motor protein at the kinetochore or areeling in at the centrosome? what would it look like if the alternative hypothesis were true?

motorprotein,mark movestoward poles

147. ____ are proteins that vary in concentration during the cell cycle to regulate entry into mitosis.A. CDKsB. CyclinsC. Histones

B

148. New DNA is synthesized in which phase of the cell cycle?A. G1B. G2C. SD. M

C

149. A phosphate in DNA isA. hydrogen bonded to a baseB. covalently linked to two basesC. covalently linked to two deoxyribosesD. hydrogen-bonded to two additional phosphatesE. covalently linked to a base, a deoxyribose and another phosphate

C

150. How many bases per turn are there in the B-form of DNA?A. 10B. 6C. 12

A

151. What kind of chemical bond is found between paired bases of the DNA double helix?A. hydrogenB. ionicC. covalentD. sulfhydrylE. phosphate

A

152. One of the Meselson and Stahl experiment's key result was that when switched from 15N to 14N growth media that: A) after one complete replication there were both heavy and light DNA molecules. B) there were only intermediate weight DNA molecules. C) there were only heavy molecules. This distinguishes conservative from the other two models.

B

153. Another key result of the Meselson and Stahl experiment was that after two rounds of replication they observed the appearance of: A) intermediate weight DNA. B) heavy DNA. C) light DNA. This result distinguishes between semiconservative and dispersive replication.

C

154. The transition from metaphase to anaphase occurs whenA. MPF is formedB. separase cleaves cohesinsC. cohesins are formed

B

155. Microtubules attach to chromosomes at a specific structure. This structure is calledA. centromereB. kinetochoreC. chromatidD. spindle pole

B

156. Who obtained x-ray diffraction data on the B form of DNA?A. Maurice WilkinsB. Francis CrickC. Rosalind FranklinD. James Watson

C

157. The first conclusive proof that DNA was the genetic material was obtained by Avery. The key to this moreconclusive experiment was obtainedA. by using enzymes which digested DNA, RNA, and proteinB. by transforming bacteria with other dead bacteriaC. by using phage

A

158. Which enzyme releases the strain in the DNA molecule cause by unwinding?A. primaseB. helicaseC. topoisomeraseD. single strand binding protein

topoisomerase

159. Telomerase requires a template for DNA synthesisA. trueB. false

B

160. The lagging DNA strand is synthesized in the direction of the replication forkA. trueB. false

B

161. Promoters are not equally good at capturing RNA polymerase complexes. What does this imply aboutRNA levels in the cell?A. RNA levels are equal for all genesB. RNA levels are not constant and vary depending on the gene

B

162. Why is the variation in RNA level for genes important?A. not important, just randomB. allows the cell to turn on and off metabolic pathways in response to developmental and environmentalcuesC. allows the cell to adjust enzyme levels to that required due to properties of the enzyme and metabolicpathwayD. B and C

D

163. Dystrophin is 3685 amino acids long. The mRNA that encodes this protein is at least ?? nts longA. 3685 ntsB. 7370 ntsC. 11055 nts

C

164. Okazaki fragments areA. DNAB. RNAC. protein

A

165. The lagging strand synthesis isA. discontinuousB. continuous

A

166. Eukaryotic mRNAs are produced by splicing parts of the primary transcript to produce the mature mRNA.Which component of the splicesome is responsible for the excision reaction?A. DNAB. RNAC. protein

B

167. Which single nucleotide pair mutation that does not change the protein sequence is called a ___ mutationA. nonsenseB. missenseC. silent

C

168. What is the more likely to disrupt gene function?A. point mutationB. deletion of two base pairsC. deletion of three base pairs

B

169. If a repressor is made in the active state the operon it controls isA. normally onB. normally offC. a form of a repressible operon

B

170. If a protein binds to the promoter and increases transcription of the operon it is a form of ____ regulationA. positiveB. negativeC. feedback

A

171. Does phosphorylation of glycogen phosphorylase activate or inactivate this enzyme? activate

172. Ras is a protein that is part of a pathway that receives external cell proliferation signals (signals to divide).When the receptor binds a signal, the pathway is activated, including Ras, and this leads ultimately tostimulation of cell division. Since most of an adult human's tissues are not actively dividing, then we wouldpredict that the Ras in those tissues would beA. onB. off

B

173. What type of signal molecules need extracellular receptors?A. hydrophobicB. hydrophilicC. both

B

174. A protein kinase is an enzyme that ____A. adds a phosphate to a proteinB. removes a phosphate from a protein

A

175. Bacteria communicate with one another in a process called quorum sensing. What is the purpose of thisprocess?A. induce cell divisionB. stop cell divisionC. induce secretion of pathogenic compoundsD. induce cell death

C

176. Metazoans have both long distance and short distance signaling mechanisms. Local signaling methods arereferred to as...A. endocrineB. paracrineC. autocrineD. exocrine

B

177. Signals that require an extracellular receptor areA. smallB. hydrophobicC. hydrophilic

C

178. A G-protein coupled receptor (GPCR) binds to and hydrolyzes...A. ATPB. GTPC. cAMPD. glucose

B

179. Receptor tyrosine kinases (RTKs) are membrane receptors that attach phosphates to tyrosines. When a ligandbinds to the receptor what happens to cause the phosphorylation?A. the receptor is destroyedB. the receptor hydrolyzes cAMPC. the receptor forms a dimerD. the receptor moves from the membrane to the cytoplasm

C

180. Calcium levels are usually much higher outside than inside the cellA. trueB. false

A

181. The initial response to a signal for apoptosis is transmitted to the...A. nucleusB. golgi apparatusC. lysosomeD. mitochondria

D

182. What was the proof that the agent causing TMV was not a toxin?A. it could pass through a small pore filterB. the agent could be repeatedly passed from plant to plantC. none of the above

B

183. Viruses are not living because they lackA. genetic materialB. protein synthesis capabilityC. proteinD. lipid

B

184. Ligand gated ion channels signal by pumping ions using ATPA. trueB. false

B

185. A kinase does what to a protein?A. adds a phosphate to an amino acidB. removes a phosphate from an amino acidC. adds a ubiquitin molecule to a proteinD. removes a ubiquitin molecule from a protein

A

186. Multiple step signal transduction pathways allow for the following featuresA. reversible signalingB higher levels of signal amplificationC. more complicated regulation D. both B and CE. none of the above

D

187. A G-protein coupled receptor can release calcium by activating the plasma membrane bound enzyme ____A. glycogen phosphorylaseB. phospholipase CC. protein kinase AD. calmodulin

B

188. Apoptosis has which of the following properties?A. responsible for morphogenesisB. the target organelle of the initial signal is the Golgi apparatusC. is cell death due to injuryD. results in the release of the cell contents

A.

189. Retroviruses have which enzyme in the capsid?A. RNA polymeraseB. DNA polymeraseC. reverse transcriptaseD. topoisomerase

C

190. New forms of influenza occur by recombination between viruses. This is calledA. antigenic driftB. antigenic shift

B

191. Influenza virus RNA is first imported into the nucleus and replicated to make mRNA. It is thereforeA. a plus strand virusB. a negative strand virusC. a retrovirusD. DNA virus

B

192. Plasmids are used instead of the bacterial chromosome becauseA. they are smaller and contain fewer restriction sitesB. they have antibiotic resistance genesC. they are in higher copy number in the bacteria than the chromosomeD. all of the above

D

193. PCR amplifies specific DNA sequences due to the use ofA. primersB. DNA polymeraseC. cyclingD. enzymes

A

194. Antigenic shift is caused byA. mutationB. recombinationC. DNA replicationD. RNA replicaiton

B

195. A process that selectively amplifies DNA is called ___A. genetic engineeringB. metabolic engineeringC. DNA cloningD. DNA sequencing

C

196. The following term probe refers to the following:A. a circular DNA with an origin of replicationB. a vector with an antibiotic selection markerC. a small piece of DNA which is used to identify a specific DNA sequenceD. an enzyme which cuts DNA at a specific sequence

C

197. Which of the following is a class of enzymes which cut DNA molecules at a specific sequence and can leave shortsingle strand regions at the cut site?A. DNA ligasesB. restriction enzymesC. isomerasesD. mutases

B

198. DNA fragments generated by restriction enzymes can be separated by size and detected using a dye using which ofthe following?A. gel electrophoresisB. centrifugationC. chromatographyD. electroporation

A

199. transgenic animals allow researchers to...A. produce animals that mimic human disease statesB. understand the function of specific genes in an intact animalC. understand the interactions of genes in an organismD. all of the above

D

200. The use of sequencing random fragments instead of the three-stage approach is now the preferred approach forobtaining genome sequences is due toA. faster and cheaper DNA sequencingB. robots for cloning DNA fragmentsC. improvements in physical mapping

A

201. The analysis of DNA sequences obtained from a mixture of organisms is calledA. genomicsB. proteomicsC. metagenomicsD. paragenomics

C

202. A primary concern of bioinformatics is gene annotation. This is theA. assignment of a function to a geneB. identification of genes including determining introns, and exons in the genomeC. naming genes

B

203. Transposons and Retrotransposons are agents of evolution. They can affect the fitness of an organism by A. coding for new proteinsB. changing the expression pattern of existing genesC. creating point mutations in existing genes

B

204. Duplicated genes can be expressed in different tissues or developmental stages because theyA. produce different proteinsB. have different control elementsC. have a different number of introns

B