Cell cycle 2.6.1 Flashcards
What is the cell cycle?
The sequence of events between mitotic divisions, experienced by all cells.
What two ways can eukaryotic cells divide by?
Mitosis and meiosis
How are all cells formed
By the division of existing cells
What are the two distinct parts of the cell cycle?
The m phase and interphase
What phase are involved in interphase?
G1 phase, S phase, and G2 phase
What are the two sections of M phase?
- Mitosis
- Prophase, metaphase, anaphase, telophase - Cytokinesis
What is cytokinesis
Division of the cytoplasm
What occurs in G1 phase?
The cell grows and new organelles and proteins are made.
What occurs in S phase?
DNA replication
What occurs in G2 phase?
The cell continues to grow
What is the G0 phase?
The stage where the cell moves out of the cell cycle, which can either be permanent or temporary
Give 3 reasons for G0
- Apoptosis (cell death)
- Differentiation (cell becoming specialised, therefore cannot divide)
- Senescence (permanent cell arrest, often due to cells only being able to divide a set number of times)
How is the cell cycle regulated?
By checkpoints
What is involved in the G1/S checkpoint?
Checks that the chemicals needed for replication are present and for any damage to DNA
What is involved in the G2/M checkpoint?
Checks the cell is ready for mitosis and that all DNA has been replicated
What are additional checkpoints used for in the cell cycle?
To prevent uncontrolled division that would lead to tumours/cancer, stops the cycle being reversed, and ensures DNA is replicated.
What does the length of interphase depend on?
The role of the cell
How long do seeds remain in G0 for?
Until germination occurs
Which cells remain in G0?
Specialised cells such as nerve and muscle cells.
