Download Cell Growth and Division

Cell Growth and Division
The Cell Theory – Pg. 170
I.
Why do cells divide?
A. DNA “overload” – If the cell become to large, the information
stored in the DNA does not meet the cell’s needs.
B. Surface area to volume ratio – Fig. 10-2 –
II.
Cell Division – the process by which a cell divides into two new
daughter cells
A. Chromosomes – composed of DNA & proteins; carry genetic
information; every organism has a specific number; Fig. 10-3
1. Chromatid –
2. Centromere –
III.
The Cell Cycle – series of events that cells go through as they grow
and divide – Fig. 10-4, 10-5
A. Interphase – period of the cell cycle between cell division
1. G1 –
2. S –
3. G2 –
B. Cell division/M phase – KNOW!!!!
1. Mitosis
a. prophase
1.
2.
3.
b. metaphase
1.
2.
c. anaphase
1.
d. telophase
1.
2.
3.
2. Cytokinesis – division of the cytoplasm, usually occurs
during late anaphase/early telophase; each new cell receives
one set of chromosomes and half of the organelles – Fig. 106
a. animal cells –
b. plant cells –
IV. Regulating the Cell Cycle
A. When cells “touch” other cells they stop dividing, therefore, cell
division can be turned “on” or “off”. – Fig. 10-7
B. Cell cycle regulators – Fig. 10-8
1. cyclins –
2. Internal regulators –
3. External regulators –
a.
b.
C. Cancer – uncontrolled cell growth