BIOS222 Exam 4 Study Guide Fall 2024 PDF

BI0S222 Exam 4 Study Guide Fall 2024 Past exam questions with answers More questions will be added from the Kahoot and regular quiz from Friday’s class/ Watch for updates to this file. 1. A ligand is a. a thing b. a thing that binds to a thing c. a thing that is...

BI0S222 Exam 4 Study Guide Fall 2024 Past exam questions with answers More questions will be added from the Kahoot and regular quiz from Friday’s class/ Watch for updates to this file. 1. A ligand is a. a thing b. a thing that binds to a thing c. a thing that is famous d. a thing that cannot bind to another thing 2. Every signaling pathway must have its own unique ligand and receptor a. True b. False 3. An animal cell receiving no signals a. Is likely to die b. Is likely to live c. Is likely to be a stem cell d. Is at peace 4. Gbeta and Ggamma are a. only active when they bind to GTP b. bound to Galpha in the resting state c. intracellular receptors d. activated second messengers when they are bound to Galpha 5. A dimeric ligand is important for the activation of a. All receptors. b. GPCRs. C. ion channel-coupled receptors. d. enzyme coupled receptors 6. A receptor tyrosine kinase a. Can phosphorylate itself b. Cannot phosphorylate itself c. Is phosphorylated on serine or threonine 7. In Earl Sutherlands work the first messenger that led to his discovery of the 2nd messenger cAMP was a) cAMP b) Epinephrine c) Insulin d) Galpha 8. treating a cell with an antibody against a receptor tyrosine kinase can cause it to form dimers leading to receptor a) Degradation b) Activation c) Endocytosis 1  d) Inactivation 9. If kinase activity causes a receptor tyrosine kinase to become phosphorylated in the course of activation, then return to the resting state will depend on a) Preventing further kinase activity b) Preventing further ligand binding to receptor c) Removal of phosphate from receptor by phosphatase d) All of the above contribute to return to the resting state. 10. M-CDK is most active when its a. Phosphorylated at inhibitory sites b. not bound to cyclin c. bound to cyclin d. in S phase of the cell cycle 11. Wee1 kinase a. Adds a stimulatory phosphate to M-CDK b. Adds an inhibitory phosphate to M-CDK c. Removes a stimulatory phosphate from M-CDK d. Removes an inhibitory phosphate from M-CDK 12. Molecules that normally put the brakes on the cell cycle are called a. Cancer genes b. Tumor suppressors c. Mitogens d. Killjoys 13. Binding of this molecule to its receptor leads to release of Rb block against entry to the cell cycle a. Halogen b. nitrogen c. mitogen d. glycogen 14. phosphorylation of nuclear lamins is responsible for disassembly of the nuclear envelope at the start of mitosis. The kinase that is responsible is a) Phosphorylase kinase b) M-CDK c) Sevenless d) Protein kinase A 15. After replication of DNA, sister chromatids are held together by a) Histones b) Spindle microtubules c) Cohesins d) Duct tape 2  16. Phosphorylation by wee1 kinase has a _________________ effect on the activity of M-CDK A) Positive B) Negative C) Neutral D) Irreversible 17. P53 protein is a a) Oncogene b) Cyclin c) Cyclin-dependent kinase d) Tumor suppressor 18. Retinoblastoma protein is a a) Oncogene b) Cyclin c) Cyclin dependent kinase d) Tumor suppressor 19. A licensing factor has this effect on DNA replication a. Limits it to once per cycle b. Allows more rounds of replication with a good record c. Slows it down d. Speeds it up. 20. Cohesins are the agents that link A. microtubules to chromosomes B. polar microtubules to other polar microtubules C. sister chromatids to each other D. lamins to the nuclear envelope 21. condensins are agents of a. chromatin condensation b. chromatin destruction during apoptosis c. DNA packaging in nucleus d. Cell shape change 3 22. DNA damage a. Is fatal to cells b. Is not believed to happen in cells c. Causes a pause in progress through the cell cycle d. Causes cells to move quickly through mitosis 23. Force production to segregate chromosomes at mitosis is provided through a. Astral microtubules b. Kinetochore microtubules c. Polar microtubules d. All of the above 24. Kinetochore microtubules a. get longer as anaphase proceeds b. get shorter as anaphase proceeds c. stay about the same d. first get shorter, then get longer 25. polar microtubules a. get longer as anaphase proceeds b. get shorter as anaphase proceeds c. stay about the same d. first get shorter, then get longer 26. At which of the following sites would you expect to see a plus-end-directed kinesin family member that contributes to anaphase chromosome movements a. Kinetochore microtubule (at – end) b. Plasma membrane c. Polar microtubule overlapping region d. All of the above 27. p53 is activated in response to DNA damage a. By phosphorylation b. By dephosphorylation c. By binding to the p21 protein d. By eliminating the p21 protein 4  28. A chromosome can be plucked out of the spindle of a live cell undergoing mitosis. As a result: a. daughter cells will end up with either one chromosome too many or one too few b. division will be halted by spindle assembly checkpoint c. p53 will be activated d. The DNA damage checkpoint will halt division 29. After replication of DNA, sister chromatids are held together by e) Histones f) Spindle microtubules g) Cohesins h) Duct tape 30. Astral microtubules contribute to a) anaphase B chromosome movements b) anaphase A chromosome movements c) telophase chromosome movements d) prophase chromosome movements 31. A cell’s karyotype is best observed and evaluated at a) Interphase b) G2 phase c) Metaphase of mitosis d) Anaphase of mitosis 32. An action potential begins with a) the opening of voltage-dependent Na+ channels b) The opening of voltage dependent K+ channels c) The activity of the NaK ATPase d) The opening of voltage dependent Ca2+ channels 33. The chromosome movements of anaphase A of mitosis are based on a) Lengthening of microtubule population labeled 6 b) Shortening of population 6 c) Shortening of population 1 d) Shortening of population 2 5  34. Astral microtubules are the population labeled e. 1 f. 6 g. 3 h. 2 35. Almost immediately after opening of Na+ channels in an action potential the membrane is repolarized by the opening of a. mechanically gated ion channels b. ligand gated ion channels c. voltage gated potassium channels d. voltage gated glucose channels 36. synaptic vesicles are agents of a. regulated secretion b. electrical signaling c. both a and b 37. synaptic vesicles release their content into a. the presynaptic cell cytoplasm b. the postsynaptic cell cytoplasm c. the synaptic cleft d. the axon 38. The electron micrograph in the figure is from a collection from Keith Porter, “the father of cell biology.” It shows 2 epithelial cells adhering to one another. The structures labeled “F” are microvilli and they are located at the 6  a. apical domain b. basal domain c. lateral domain d. eminent domain 39. In the same micrograph the zone of cell-cell contacts between the two cells meanders down the left part of the picture. The contact region that prevents molecules from diffusing between cells to get past the epithelium is a) the tight junction (ZO) b) the adherens junction (ZA) c) the desmosome (D) d) none of the above 40. This type of cell-cell junction is intimately associated with a belt of actin filaments a. Adherens junction b. Tight junction c. Desmosome d. None of the above 41. A transmembrane protein with an extracellular domain that binds to the same domain on a neighboring cell to provide adhesion is considered to be a. Heterophilic b. Homophilic c. Amphiphilic d. heteromorphic 42. gap junctions a. allow cells to have a gap between them 7  b. allow small molecules to pass freely between 2 connected cells c. prevent small molecules from passing between cells d. are only seen in single cell organisms 43. John Gurdon won the Nobel prize for his work showing that you can clone a frog (or a cow or your pet dog) by removing the nucleus from an egg and replacing it with a nucleus from a) ES cell; b) single cell embryo; c) adult skin cell; d) iPS cell 44. Which of the following are shared by oncogenes and tumor suppressors a. Both are found to be mutated at high frequencies in human populations b. Both tend to be recessive mutations c. Both tend to be dominant mutations d. Both tend to exhibit a gain of function in the mutant state 45. Ross Cagans fly avatars are transgenic flies he is using to show that a) There are mutant fly proteins that cause fly cancer b) Expressing normal versions of human genes cause cancer in the fly c) Expressing genes with mutations that cause cancer in humans also cause cancer in flies d) Expressing genes with mutations that cause cancer in humans don’t cause cancer in flies 46. Oncogenes are, simply put, mutant forms of a. Genes that promote cell growth and division in normal cells b. Genes that prevent cell growth and division in normal cells c. Genes that usually have no role in growth and division in normal cells d. Genes that don’t fall into any particular categories 47. Which of the following is not pluripotent? a) ES cell b) Adult skin cell c) Single cell embryo d) iPS cell 48. A stem cell that can only give rise to one specific differentiated cell type is considered to be: A) multipotent C) pluripotent E) impotent B) totipotent D) megapotent 8  49. Which of the following is not true of induced pluripotent stem (iPS) cells: A. can be generated from adult cells in the human body B. require destruction of human embryos to produce them C. produced by artificially driving expression of a set of key genes D. can give rise to many different adult human cell types 50. Texas Governor Rick Perry underwent a medical procedure in which he was injected with stem cells that came from: A) a human embryo B) fat tissue removed from his own body C) conversion of his own skin cells into pluripotent stem cells D) a mouse embryo E) an elephant embryo 51. A risk that goes with introduction of embryonic stem cells into the Adult human body is i. that it won’t have any effect ii. that they might develop into a tumor iii. that they will be rejected as foreign iv. all of the above 52. Retinoblastoma gene defects do not always result in cancer because a) the cancer is caused by a virus that may or may not be present in a given time or place b) one copy in Rb patients is defective at birth, the other copy becomes mutated somatically later in life (sometimes but not always) c) cancer is not a genetic disease d) the gene is only one of many that control onset of cancer 53. Viagra impacts signal transduction by v. increasing transduction of the nitric oxide signal vi. blocking a negative regulator of nitric oxide (NO) signaling vii. delivering the nitric oxide signal to a different second messenger viii. increasing the amount of nitric oxide made in response to NO signalling 9  54. tyrosine kinase receptor activation leads to the appearance of phosphotyrosine residues____________________ A) At the ligand binding site B) At the cytoplasmic domain C) in downstream components of the signaling pathway D) in the transmembrane domain 55. small GTP binding proteins like ras and ran are active when they 1. are bound to ATP 2. are bound to GDP 3. are bound to ATP 4. are bound to GTP Pathway 1 Pathway 2 Use the above 2 diagrams to answer the five questions below: 10  56. Ligand binding outside the cell leads to a change in enzyme activity inside the cell A) True in pathway 1 B) True in pathway 2 C) True in both pathways D) Neither pathway 57. The second messenger could be cAMP A) True in pathway 1 B) True in pathway 2 C) True in both pathways D) Neither pathway 58. The ligand is a dimer A) True in pathway 1 B) True in pathway 2 C) True in both pathways D) Neither pathway 59. The receptor has 7 transmembrane domains A) True in pathway 1 B) True in pathway 2 C) True in both pathways D) Neither pathway 60. GTPase activity terminates the activated state of the system A) True in pathway 1 B) True in pathway 2 C) True in both pathways D) Neither pathway 61. What gets phosphorylated on tyrosine in response to activation of a receptor tyrosine kinase A. the extracellular domain of the receptor B. the cytoplasmic domain of the receptor C. the next component downstream of the receptor D. the ligand for the receptor 11  62. Sound is transduced by the outer hair cells of your inner ear via A) Nuclear receptors B) Enzyme linked receptors C) Mechanically gated ion channels D) G protein coupled receptors 63. Viagra exerts its effect on signaling by A) Delaying the end of the activated state of signaling B) Accelerating the end of the activated state of signaling C) Getting to the activated state of signaling more rapidly D) Delaying the arrival of the activated state of signaling 64. The pathway affected by Viagra is A) Phospholipase C signaling B) GPCR signaling C) Nitric oxide signaling D) Nuclear receptor signalling 65. Ras is an intermediate in A) Phospholipase C activation B) Akt activation C) GPCR signalling D) Tyrosine kinase signaling. 66. one of the following is not involved in turning off / resetting a pathway for signalling A) removal of a phosphate from the head group of an inositol phospholipid B) a G alpha trimeric G protein giving up a GDP and replacing it with a GTP C) hydrolysis of GTP bound to a small GTP binding protein D) Removing phosphates from tyrosines in a growth factor receptor 67. protein kinase A is an effector of A) nuclear receptor signaling B) ion gated channel signaling C) GPCR signaling through phospholipase C D) GPCR signalling through adenylyl cyclase 12  68. The time it takes to reset an action potential is A) in the millisecond range B) in minutes C) In hours D) In about a Day 69. Voltage gated calcium ion channels in the presynaptic membrane are responsible for A) Terminating an action potential B) Release of neurotransmitter from the presynaptic cell C) Release of neurotransmitters from the postsynaptic cell D). Propagation of the action potential down the length of the axon 70. Neurotransmitter gated ion channels A) do not contribute to action potentials B) regenerate an action potential in the presynaptic cell C) regenerate an action potential in the axon D) regenerate an action potential in the post synaptic cell 13