Download Cell Cycle Regulators

GUIDED READING 10.3 (GEISLER)
Name ___________________________
Class ________ Date: _____________
1. How are cancer cells different _______________________________________?
2. Not all cells move through the cell cycle _______________________________________. In the
human body, most muscle cells and nerve cells ______________________________________
______________once they have developed.
3. In contrast, the cells of the ______________________________________________, and cells in the
bone marrow that make blood cells, __________________________________ __________
throughout life.
4. Cells in a Petri dish will _______________________________________ until they come
_______________________________________with other cells.
5. What would happen if the cells _______________________________________?
6. If cells are removed from the _______________________________________, however, the cells
bordering the open space will begin dividing _____________________________ __________the
empty space. These experiments show that the controls on cell growth and cell division can be
_______________________________________.
7. Scientists can observe the effects of _______________________________________ in the
laboratory by placing some cells in a Petri dish ________________________________________.
8. Most cells will grow until they form a thin layer _________________________________________
the dish, as shown in Figure 10-7. Then, the cells stop growing.
9. When cells come into contact with other cells, they _____________________________________
__________.
10. When an injury such as a cut in the skin or a break in a bone occurs, cells at the edges of the injury
are _______________________________________ rapidly. This action produces new cells, starting
_______________________________________.
Cell Cycle Regulators
11. There are two types of regulatory proteins: those that occur _____________________________
__________ and those that occur outside the cell.
12. For many years, biologists searched for a substance that might ___________________________
__________________ —something that would "tell" cells when it was ______________________
___________________ their chromosomes, or enter another phase of the cycle.
13. _______________________________________, including Tim Hunt of Great Britain and Mark
Kirschner of the _______________________________________, discovered that cells in mitosis
contained a protein that when injected into ___________________________________________,
would cause a mitotic spindle to form.
GUIDED READING 10.3 (GEISLER)
Name ___________________________
Class ________ Date: _____________
14. They decided to call this protein ________________ because it ________________________
_______________ the cell cycle.
15. More recently, dozens of _______________________________________ have been discovered that
also help to regulate the cell cycle.
16. _______________________________________ allow the cell cycle to proceed only when certain
processes have happened inside the cell.
17. _______________________________________ to events outside the cell are called external
regulators.
18. External regulators direct cells to_______________________________________ the cell cycle.
_______________________________________ among the most important external regulators.
Molecules found on the surfaces _______________________________________ often have an
opposite effect, causing cells to _______________________________________ their cell cycles.
19. Proteins that respond to events inside the cell are called _________________________________
____________________.
20. Another regulatory protein prevents a cell _______________________________________ until all its
chromosomes are attached to _______________________________________.
21. A _______________________________________ is removed from a cell in mitosis. The sample is
injected _______________________________________ in G2 of interphase. As a result, the second
cell enters mitosis.
Uncontrolled Cell Growth
22. What causes the _______________________________________ that characterizes cancer? The
various forms of cancer have many causes, including _________________________________
_____________________________________________.
23. _______________________________________, have one thing in common: The control over the
cell cycle _______________________________________.
24. _______________________________________ do not respond to the signals that regulate the
_______________________________________.
25. Why is cell growth ________________________________________________? The principal reason
may be that the consequences of _______________________________________ in a multicellular
organism are very severe.
26. _______________________________________ do not respond to the signals that regulate the
_______________________________________. As a result, they divide uncontrollably and form
masses of cells called tumors that can damage the surrounding tissues.
GUIDED READING 10.3 (GEISLER)
Name ___________________________
Class ________ Date: _____________
27. An astonishing number of cancer cells have a _______________________________________,
which normally halts the cell cycle until all chromosomes ______________________________
______________. _______________________________________ p53 genes cause the cells to
lose the information needed to respond to signals that would ________________ ______________
_________________________________.
Stem Cells: Promises and Problems
28. _______________________________________, every cell was produced by mitosis from a small
number of cells _______________________________________.
29. Stem cells are _______________________________________ that have the potential to
differentiate—to become specialized in _______________________________________ —into a
wide variety of cell types.
30. Stem cells in the _____________________________________________________, produce more
than a dozen types of blood cells, replacing those lost ___________________________________
___________________________________________.
Stem Cells in Medicine
31. _____________________________________________________________________________
solution to this problem. Recently, researchers have found that___________________________
________________ can reverse the effects of brain injuries in mice. There is hope that the same
__________________________________________ and that stem cells might be used to reverse
______________________________________________________________________________.
32. It also may be possible to use stem cells to _______________________________________, to
replace heart valves, and to reverse _______________________________________.
33. For example, the body is not able to produce new neurons to repair ___________________
___________________________________________________, such as those that cause paralysis.
Because of this, at present, there is no way for doctors __________________________
________________________________________________ to people who are paralyzed.
Sources of Stem Cells
34. However, _______________________________________ cells are taken from human embryos
these techniques raise _____________________________________________________________.
Because of such issues, _______________________________________________ is highly
controversial.
35. Researchers have found that ________________________________________________________
______ cells sometimes can be grown from adult, _______________________________________.
GUIDED READING 10.3 (GEISLER)
Name ___________________________
Class ________ Date: _____________
10-3 Section Assessment (REQUIRED; please write all answers in complete sentences.)
1.
2.
3.
4.
5.
What chemicals regulate the cell cycle? How do they work?
What happens when cells do not respond to the signals that normally regulate their growth?
How do cells respond to contact with other cells?
Why can cancer be considered a disease of the cell cycle?
Critical Thinking/Formulating Hypotheses:
Write a hypothesis about what you think would happen if cyclin were injected into a cell that
was in mitosis.
Designing an Anticancer Drug (Alternative Assessment; extra credit if completed)
Imagine that you are developing a drug that will inhibit the growth of cancer cells. Use your
knowledge of the cell cycle to describe how the drug would target and prevent the multiplication
of cancer cells. Use the Internet to compare your anticancer drug with those currently in use.