Mitosis Flashcards
Name 3 parts of the cell cycle
Interphase (majority of cycle)
mitosis (double the cytokinesis section)
cytokinesis (half the mitosis section)
Name the 5 stages of mitosis (in order)
Interphase Prophase Metaphase Anaphase Telophase ( + cytokinesis)
Describe at least 3 reasons why mitosis happens
- growth of tissues
- replacement of lost cells
- repair of damaged tissue
- asexual reproduction
- formation of clones of T and B lymphocytes
- cells abnormally divide uncontrollably to form tumours
Name the parts of a chromosome
Chromatids
Centromere
What is a chromatin?
DNA when it is not wound up tightly as a chromosome
What is a chromosome?
compact X or I shaped form of chromatin formed during cell division
What are chromatids?
two identical arms of an X-shaped chromosome
What is the centromere?
point at which chromatids are joined together
What are homologous chromosomes?
two chromosomes originating from each parent,containing the same genes but different alleles (e.g both chromosome 22 but 1 from each parent)
Describe the interphase ( + draw)
- The cell grows and the DNA replicates itself
- The chromosomes are not visible
- Not strictly part of mitosis
Describe the prophase ( + draw)
- Chromosomes condense + become visible
- Centrioles move to opposite ends/poles of the cell
- Spindle apparatus form spindle fibres (part of the spindle apparatus) at the centrioles
Describe the metaphase ( + draw)
- The nuclear envelope breaks down
- Chromosomes align along the equator/centre of the cell pulled by spindle apparatus
Describe the anaphase ( + draw)
- Centromeres split, allowing chromatids to separate
- Chromatids move towards the poles, pulled by the spindle fibres
Describe the telophase ( + draw)
- Spindle fibres disperse
- Nuclear envelope reforms
- Chromosomes decondense
Describe cytokinesis
A ring of protein filaments form around the equator of the cell, which then tightens + splits the cell into two
