U1AOS1 Cell Cycles Flashcards
Binary fission
Most prokaryotes reproduce binary fission, where one parent cell gives rise to two identical daughter cells
First stage of the prokaryotic cell cycle
DNA replication, from the origin of replication duplicating the DNA as it works its way along
2nd stage of the prokaryotic cell cycle
Two seperate chromosomes attach themselves to the cell membrane in different parts of the cell
3rd stage of the prokaryotic cell cycle
Cell elongation, the cell grows longer, to around 2x as long as
4th stage of prokaryotic cell cycle
Z-ring formation, A ring made of protein fibres
5th stage of prokaryotic cell cycle
Once the z-ring has formed, it constricts, pulling in the cell membrane and cell wall
6th stage of prokaryotic cycle
Z-ring brings together other proteins to synthesise a new cell wall called a septum along the equator of the cell
7th stage of prokaryotic cell cycle
Cytokinesis, cell wall degrading enzymes digest the centre of the cell wall, dividing the septum and resulting in two identical cells
Eukaryotic cell cycle
Cells divide through mitosis
How do single celled eukaryotes reproduce?
Through asexual mitosis
Stages of eukaryotic cell cycle
Interphase: g1, s, g2
Mitosis: p, m, a, t, cytokenesis
What occurs in the s phase
DNA replication
Where does DNA replication occur
S phase
What are the organelles involved in mitosis
Nucleus, mitotic spindles and micro tubules
1st stage of mitosis
Prophase: the chromatin starts to condense, becoming visible and the centrioles seperate from each other and begin to form spindle fibres. centrioles move to poles of the cell. nuclear membrane is gone and chromosomes begin to move to centre of cell. Now look like an X
