Mitosis Flashcards
What is a centromere
A small section of DNA and associated proteins that attaches the sister chromatids to each other
What does a chromosome consist of
- Replicated one = 2 chromatids each with a DNA sequence identical to the other
- AKA sister chromatids
What happens to the chromatids when the centromere splits
Each chromatid becomes an individual chromosome
What are the parts of the cell cycle
- Gap 1 ( G1 )
- Synthesis ( S )
- Gap 2 ( G2 )
- Mitotic stage ( M )
Explain what happens in G1
This is normally the longest period of the cell cycle and stretches from the time of cytokinesis and the next round of DNA synthesis
Explain what happens in G2
This is the preparatory stage for mitosis. Organelles are replicated and proteins required in mitosis, e.g. for the formation of microtubules, are produced
Explain what happens in S
This refers to the phase in which the chromosomes are duplicated, i.e. DNA synthesis
Explain what happens in M
This involves the division of chromosomes and the subsequent cytokinesis
Explain G1 checkpoint
- Cell cycle checkpoint
- Apoptosis will occur is DNA is damaged and cannot be repaired
- Otherwise the cell is committed to divide
- Check cell and DNA for damage
Explain M checkpoint
- Spindle assembly checkpoint
- Mitosis will not continue if chromosomes are not properly aligned
Explain what needs to be ensured in the cell for DNA replication and cell division
No problems with cell
DNA isn’t damaged
Replicated properly
Explain G2 checkpoint
- Mitosis checkpoint
- Mitosis will occur if the DNA has replicated properly
- but if there’s any problems with DNA, apoptosis will occur
What type of cells undergo cell division
Normal and undamaged cells
Explain mitosis fully
- Main purpose of mitosis in eukaryotes is growth and the repair of damaged tissue
- This involves the somatic cells, i.e. All cells not involved in reproduction
- There are, however, plant, animal, fungi and prokaryotes that reproduce through mitosis and this is called asexual reproduction
What are daughter cells
- Outcome of mitosis which are identical to parent cell ( exact same number of chromosomes as parent cell )