Cell division (Mitosis) Flashcards
What is mitosis?
It is a type of cell division. The mother cell undergoes division and creates two daughter cells that are original to each other and the original cell. There is no change in the chromosome number
What are the stages of the cell cycle?
First there is interphase where the cell grows and accumulates nutrients needed for duplicating DNA. Then there is mitosis and cytokinesis where the cell duplicates in splits into two distinct, identical cells
Why is mitosis important?
It replaces cells that wear off naturally (skin) and existing cells undergo mitosis to produce new cells for replacement. It is also helps repair tissues/organs damaged by accident
Phases of mitosis.
- Interphase
- Prophase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
- Interphase
Prepares for division. Growth and duplicating DNA
- Prophase
Chromosomes form (2 pairs of chromatids connected by centromere) and the centrosome moves towards the poles
- Metaphase
The chromosomes form a line along the equator of the cell. Spindle fibres from the centrosome connects to the centromere
- Anaphase
Spindle fibres contract and pull chromosomes apart towards opposite sides of the cell. Each chromatid is a single strand of DNA
- Telophase
2 groups of 4 chromosomes are now present. Nucleus forms and cytokinesis takes place separating into two cells
Differences between mitosis in animal and plant cells
Animal:
- Centrosome forms spindle fibres
- Cytokinesis occurs by a constriction of the cell membrane until two cells are formed
Plants:
- Cytoplasm forms spindle fibres
- Cytokinesis occurs by the making of a new cell wall in the middle region of the cell