Chapter 12 The Cell Cycle Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

Prokaryotic Division Why don’t prokaryotic cells need to go through the same cell cycle as eukaryotic cells? Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

S Phase How might you prove experimentally that DNA replication (and therefore the replication of chromosomes) happens during the S phase of the cell cycle and not during mitosis? Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

Chromosomes in the Cell Cycle At what part of the cell cycle would you see a chromosome that looks like this? Give your reasons. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

Evolution What do the differences among the division of these cells demonstrate? Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

Kinetochore Which of the following best describes the kinetochore? a structure composed of several proteins that associate with the centromere region of a chromosome and that can bind to spindle microtubules the centromere region of a metaphase chromosome at which the DNA can bind with spindle proteins the array of vesicles that will form between 2 dividing nuclei and give rise to the metaphase plate the ring of actin microfilaments that will cause the appearance of the cleavage furrow the core of proteins that forms the cell plate in a dividing plant cell Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

Rate of Mitosis If you were to examine a sample of connective tissue cells from a small but adult mammal and a second sample from a fetus of the same species, in which would you expect to find more cells undergoing mitosis? Why? Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

Regulation of the Cell Cycle A Regulation of the Cell Cycle A. What would you expect to happen if you fuse a cell in S with a cell in G1? Why? B. What would you expect to happen to a nucleus from a G1 cell if it is introduced into an enucleated M cell? Why? Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

Regulation Which of the following would need to be present to produce a realistic signal to control the cell cycle? (More than one may be required.) a set of molecules that are sensitive to fluctuations in the abundance of regulators protein kinases molecules that activate kinases molecules that degrade activators ability of the regulators to respond to signals from outside the cell signals from cellular surveillance Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

Cancer Cells At which part of the cell cycle would you expect that a change in regulation could result in cancer? Provide a reason for your answer. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.