TOPIC: The Cell Cycle
QUESTIONS & VOCAB.
Why do cells divide?
Name: ___________________
Class: ___________________
Date: ___________________
NOTES:
 DNA is unable to keep up with all the cell’s needs
 The larger the cell, the harder it is to move materials across the cell
membrane
Exchanging Materials
 The cells ability to get rid of waste deals with surface area
 As cell length increases, volume increases faster than surface area
 As the ratio of surface area to volume decreases the cell ability to
move particles out decreases
What occurs during
prokaryotic cell division?
1. replication of DNA
2. cell contents separate into 2 parts
Eukaryotic Cell Division

A series of events that cells go through as they grow and divide

Interphase & M phase (mitosis)
What is the Cell Cycle?
What are the TWO main
parts of the cell cycle?
Describe INTERPHASE
1. Interphase = Resting stage
a. DNA is in the form of chromatin
b. 3 Phases
What are the THREE parts
of interphase and what
happens during each part?
1. G1 phase – cell growth
2. S phase – replication of DNA
3. G2 phase – replication of organelles for cell division
2. M phase (MITOSIS): Cell division; division of nucleus
Describe M PHASE
QUESTIONS & VOCAB.
When will cells stop
growing and dividing?
NOTES:
 When they touch other cells
What controls the cell
cycle?

Cell proteins called cyclins

Cells that do not respond to the signals that regulate the growth of
most cells

These cells can form masses of cells called tumors

These cells normally grow at a faster rate than normal cells
What gene is defected in
most cancer cells?

p53 gene
What does the p53 gene do
in normal cells?

p53 halts the cell cycle until the chromosomes have been properly
replicated
CANCER
What causes cancer?