Download Chapter 10: Cell Growth and Division

Chapter 10: Cell Growth and Division
10-1: Cell Growth
How do living things grow?
Limits to Cell Growth
•
2 reasons why cells divide rather than grow?
1. ________________________________________________________________
________________________________________________________________
2. ________________________________________________________________
________________________________________________________________
DNA “Overload”
• DNA is found in the _______________ of the cell
• Why can’t a cell grow without limit? ____________________________
___________________________________________________________
Exchanging Material
• What substances may move through the cell membrane?
___________________________________________________________
• The rate materials exchange depends on the _______________ of the cell
• The rate materials are used depends on the cell’s ______________ (size).
Ratio of Surface Area to Volume
• Surface to volume ratio
• ______________ increases faster than _______________
– The cell uses matreials faster than it can get them in
• Town analogy: ______________________________________________
___________________________________________________________________
Asexual Reproduction
Asexual reproduction - ________________________________________
____________________________________________________________
____________________________________________________________
Asexual reproduction is a _________________________way for an
organism to produce a large number of offspring.
Both prokaryotic and eukaryotic single-celled organisms and many
multicellular organisms can reproduce asexually.
Ex. hydra, bacteria,
yeast
Sexual Reproduction
In sexual reproduction, offspring are produced by the _______________
_______________________________________________
The offspring produced inherit some genetic information from both
parents, therefore they are ________________________.
Most animals and plants, and many single-celled organisms, reproduce
sexually.
Division of the Cell
• Cells divide to form two new cells called ______________________
• This process is called _______________________
• Before it can occur, what has to happen? _________________________
___________________________________________________________
________
 _____________________________________________ (chromosome)
so it can be divided precisely
Section 10-2: Cell Division
• ___________________ – less complicated division
– Replicate DNA – divide everything up between 2 cells.
• ___________________ – more complicated division
2 Main Stages
– ___________________ – division of the nucleus
– ___________________ – division of cytoplasm
Chromosomes
Chromosomes – ______________________________________________
____________________________________________________________
• Every organism has a specific number of chromosomes
– Fruit flies – 4
– Dog - 78
– Carrots – 18
– How many chromosomes do humans have? _________
• Chromosomes are only visible when
_____________________________________
• Why is this? ________________________________________________
___________________________________________________________
________
• Before division, the chromosome (DNA) is ___________________
• The replicated chromosome consists of 2 identical “sister”
___________________.
– One chromatid goes to each new cell
– Held together near the center by ______________________
Chromosomes (a closer look)
• Chromatin is a complex of DNA _____________________________
_____________________________
• The DNA and histone molecules then _________________________
_________________________________.
• The chromosome “X” shape we usually see drawn is a duplicated
chromosome made of supercoiled chromatin
Cell Cycle
The ___________________ represents the events in the life of a cell.
• A series of events cells go through as they grow and divide.
• During the cell cycle: a new cell ___________, prepares for
____________ and divides into two _________________ cells.
Events of the Cycle
Interphase
–Growth Phase most time spent in this phase
–3 phases
•G1 – _______________________
•S – ________________________
•G2 – _______________________
Mitosis
• Division of the nucleus (can last hours to a few days)
• 4 phases:
1.
2.
3.
4.
____________________
____________________
____________________
____________________
Mitosis Phases
1. Prophase – first phase, longest phase
• DNA condenses into _______________________
• 2 ________________(microtubules) take positions on opposite sides of
the nucleus
• __________________ begins to form
• What is a spindle? _______________________________________
_______________________________________________________________
• Chromosomes coil more tightly
• ________________ disappears
• Nuclear _________________ breaks down
2. Metaphase – second phase, takes a few minutes
• Chromosomes line up across middle of the cell
• Microtubules connect the _________________ of each chromosome to
the two poles of the spindle
3. Anaphase – third phase
•____________________ that join the “sister” chromatids together split.
•____________________ separate (now individual chromosomes)
•The copies move away from each other to opposite sides of the cell (2 groups)
4. Telophase – fourth, final phase
•
•
•
•
____________________ uncoil and relax
_______________________ reforms around each cluster of chromosome
____________________ breaks down
A __________________ becomes visible in each daughter nucleus.
Kinetochore
• _____________________________________________________
that is an attachment site for microtubules that assist in cell division
Cytokinesis
• Division of the ___________________
• __________________________________________________
Cytokinesis – Animal
• Animal cells are surrounded by a _______________________
Animal Cell - Formation of a ____________________
Cytokinesis - Plant
• Plant cells are surrounded by a ____________________
Plant Cell - ___________________________
Cell Division - Prokaryotes
Prokaryote - unicellular bacteria with no nucleus
Binary Fission - _______________________________________________
10-3 Regulating the Cell Cycle
• Cell growth and division is very controlled
• True or False – All cells move through the cell cycle at the same rate.
Controls of Cell Division
• What happens when cells are grown in a petri dish?
___________________________________________________________________
___________________________________________________________________
• What does this experiment show?
___________________________________________________________________
• What happens in our body that is similar?
___________________________________________________________________
Cell Cycle Regulators
• Scientists have been trying to determine what regulates the cell cycle.
• Found a protein – if they inject it into a non-dividing cell, the cell enters
_______________
• What is the protein called? _____________________
Why? _____________________________________
• Cyclins regulate the timing of the cell cycle in ________________ cells.
Internal Regulators
• Proteins that respond to events ____________the cell
Ex: _______________________________________________________________
________________________________________________________________
External Regulators
• Proteins that respond to events ______________ the cell.
Ex: _______________________________________________________________
________________________________________________________________
Uncontrolled Cell Growth = CANCER
• Cancer cells do not ____________ to cycle regulators
• Results
– Divide __________________________
– Form _____________ (masses of cells) that can damage the surrounding tissue
– Cancer cells may break loose from tumors and ___________________________
_________________________________________________________________
• What are some causes of cancer?
___________________________________________________________