NadiaA
Cell Cycle and Cell Division
LO:
Understand the molecular mechanisms involved in cell cycle regulation.
-x-
Cell cycle and cell division are not the same thing
Difference between cell cycle and cell division
The stage through which a cell passes from one division to the next is called the cell cycle. Cell cycle
is divided into two phases called (i) Interphase – a period of preparation for cell division, and (ii)
Mitosis (M phase) – the actual period of cell division.
Why is cell division important?
Continuity of life
Passes on genetic info to future generations
Happens in multicellular and unicellular organisms
Growth
Repair and replacement of cells
How have we achieved our understanding of the cell cycle?
By experiments on model organisms, both unicellular organisms and multicellular
1. Unicellular reveal genetic info on cell cycle
Unicellular organisms are easy to genetically manipulate e.g. yeast
Yeast S pombe is a typical eukaryote and is rod shaped; it has all the stages of cell division
that is common among eukaryotes: G1,S,G2, M
Whereas, yeast S. cerevisiae has a different cycle; it only has G1, S, and M
Changing the temperature an organism is growing at can cause a mutation e.g.
Budding is a form of mitosis
The daughter cells will be smaller than parent cell if interphase is short- i.e. it needs to be
long to allow cell growth then the next stage can progress
Yeast mutants uses;
Can be rapidly reproduced as they have a small genome
Haploid- has single gene copy
Easy to manipulate genes e.g. deletion, replacement, alteration
Were involved in discovering cell division cycle genes (cdc genes)
2. Multicellular organisms reveal biochemistry of cell cycle
Study of early embryonic frog cells
They are large cells- 1mm diameter;
Thus easy to inject samples
1
Cell Cycle and Cell Division
LO:
Understand the molecular mechanisms involved in cell cycle regulation.
-x-
Cell cycle and cell division are not the same thing
Difference between cell cycle and cell division
The stage through which a cell passes from one division to the next is called the cell cycle. Cell cycle
is divided into two phases called (i) Interphase – a period of preparation for cell division, and (ii)
Mitosis (M phase) – the actual period of cell division.
Why is cell division important?
Continuity of life
Passes on genetic info to future generations
Happens in multicellular and unicellular organisms
Growth
Repair and replacement of cells
How have we achieved our understanding of the cell cycle?
By experiments on model organisms, both unicellular organisms and multicellular
1. Unicellular reveal genetic info on cell cycle
Unicellular organisms are easy to genetically manipulate e.g. yeast
Yeast S pombe is a typical eukaryote and is rod shaped; it has all the stages of cell division
that is common among eukaryotes: G1,S,G2, M
Whereas, yeast S. cerevisiae has a different cycle; it only has G1, S, and M
Changing the temperature an organism is growing at can cause a mutation e.g.
Budding is a form of mitosis
The daughter cells will be smaller than parent cell if interphase is short- i.e. it needs to be
long to allow cell growth then the next stage can progress
Yeast mutants uses;
Can be rapidly reproduced as they have a small genome
Haploid- has single gene copy
Easy to manipulate genes e.g. deletion, replacement, alteration
Were involved in discovering cell division cycle genes (cdc genes)
2. Multicellular organisms reveal biochemistry of cell cycle
Study of early embryonic frog cells
They are large cells- 1mm diameter;
Thus easy to inject samples
1
