The cell cycle Flashcards
1
Q
What is the Cell Cycle
A
The Cell Cycle is a Series of Events the Cell Carries Out in Preparationfor the Cell Division
2
Q
What are the stages of the cell cycle? (5)
A
- Gap 0 phase
- Gap 1 phase (G1) - preparation for DNA synthesis and cell division
- Synthesis phase (S) - Duplication of DNA
- Gap 2 phase (G2) - preparation for M phase, organelle replication
- Mitosis (M) - cell division
3
Q
Where are the checkpoints in the cell cycle (4)
A
- End of G1 phase
- Middle of S phase
- End of G2 phase
- Beginning of the M phase
4
Q
What happens in the Gap 1 Phase of the cell cycle (5)
A
- Proteins bind to the DNA - (Origin recognition complexes (ORC’s) bind to the origin of replication sites)
- RNA and protein are synthesised and ready for cell division
- The cell grows to full size
- A cell may leave the cell cycle into (G0) temporarily or permanently
- Cells may enter the cell cycle from (G0) to (G1)
5
Q
What happens in the synthesis phase of the cell cycle (3)
A
- Proteins involved in DNA synthesis are switched on, allowing DNA replication to occur
- Nuclear proteins (called histones) must also be produced (doubled). These proteins are needed to support the structure of the new DNA
- A structure called a ‘centrosome’ that supports microtubules in the cell is also duplicated
6
Q
What happens in the Gap 2 phase of the cell cycle (2)
A
- Many of the cell’s organelles (mitochondria, endoplasmic reticulum, Golgi apparatus, etc.) are synthesised and ready for cell division
- Towards the end of the G2 Phase, the DNA condenses to look more like ‘textbook’ chromosomes ready for the M Phase.
7
Q
What happens in the Mitosis phase of the cell cycle (6)
A
- Prophase (early Prophase) - spindle poles are formed at different sides of the cell.
- Pro-metaphase (late Prophase) - Spindles pull chromatids to separate sides
- Metaphase -
- Anaphase
- Telophase
- Cytokinesis
