Answer KEY BIOL 151 Quiz 9 12 25 R Phillis Please be sure to enter the following into the Dields at the top of the answer sheet Name Your Name ID Your UMass ID Section 01 Date 9 12 25 Other Quiz Multiple True False questions and have numbered answers For each numbered answer put A for True and B for False on your answer sheet unless otherwise directed Problem 1 5 For each of the following determine whether the cells is in anaphase or metaphase A Anaphase B Metaphase B1 Some but not all kinetochores are attached to spindle Hibers A2 Ubiquitin is attached to Securin B3 Sister chromatids are found lined up in the middle of the cell A4 Securin is not present in the cell A5 Cohesin is not present in the cell Problem 6 10 Which of the following are true of healthy cells and normal mitosis F6 Sister chromatids are copies of chromosomes that come from different parents T7 When cells are not in mitosis they are in interphase T8 Using microscopy mitotic spindles would be more commonly seen in transit amplifying cells than in mature differentiated cells F9 Spindle Hibers are locked into a speciHic length during metaphase F10 Chromosomes replicate during the metaphase to anaphase transition Problem 11 15 Which of the following are true about the metaphase to anaphase transition in healthy normal cells T11 Unattached kinetochores affect the binding of MAD to CDC20 T12 If Ubiquitin is attached to Securin all kinetochores must be attached to spindle Hibers T13 Cohesin disappears from cells in anaphase T14 Without Securin cells would not pause in metaphase and would progress directly to anaphase T 15 Extra chromosomes in cancer cells can be caused when cells enter anaphase prematurely There are more questions on the back of the quiz A premature anaphase B stuck in metaphase Problem 16 20 For each of the following determine whether the mutation would cause the cell to be go into premature anaphase or would be stuck in metaphase A 15 A loss of function mutation in MAD that prevents it from binding to CDC20 B16 A loss of function mutation in MAD that prevents it from responding to changes in the unattached kinetochore signal A17 A gain of function mutation in APC that causes it to add Ubiquitin to Securin even if APC was not attached to CDC20 A18 A gain of function mutation in Separase that causes it to break down both Cohesin and Securin A19 A gain of function mutation in Separase that causes the cell to make twice the normal amount of Separase A20 A gain of function mutation in CDC20 that causes it to make twice the normal amount of CDC20 Problem 21 24 The chemotherapy drug Vincristine blocks the ability of microtubules spindle Hibers to change length Which of the following would happen to dividing cells in the presence of Vincristine T21 The cells would get stuck in metaphase F22 The cells would go into premature anaphase F23 The unattached kinetochore signal would be blocked and MAD would release CDC20 F24 Ubiquitin would end up being attached to Securin 25 Self renewal signals cause stem cells to divide asymmetrically where one daughter cell stays a stem cell and the other becomes a transit amplifying cell The transit amplifying cell divides many times in response to the self renewal signal Could transit amplifying cells have a positive feedback loop in the Self Renewal signaling pathway to causes multiple cell divisions a Yes b No