Genetic analysis trends and concepts - GEN30306 - Summary of lectures and papers

Genetic analysis trends and
concepts
Minor or additional info
Terminology

Assumed knowledge meiosis and mitosis:
Meiosis = in germ cells
Mitosis = somatic cells

Mitosis: one cell divides once into two identical cells.




Mitosis consists of 5 phases IPMAT:
1. Interphase
 DNA is copied leading to two identical full sets of chromosomes
 There are two centrosomes outside of the nucleus containing centrioles
 Microtubules extend from the centrosomes
2. Prophase
 Chromosomes condense into X shapes
 Each chromosome consists of two sister chromatids containing identical information
 Chromosomes pair up so that both copies of each are together
 The nucleus membrane dissolves away
 The mitotic spindle extends across the cell between the centrioles as they move to
opposite poles
3. Metaphase
 Chromosomes line up end to end along the centre of the cell

,  The centrioles are at opposite poles and have mitotic spindle fibres extending from them
 The mitotic spindle fibres attach to each of the sister chromatids
4. Anaphase
 The sister chromatids are pulled apart pulling each copy to opposite ends of the pole
5. Telophase
 At each pole a full set of chromosomes gather
 A membrane forms around each set to form new nuclei
 The single cell pinches in the middle to form two daughter cells = cytokinesis

, Meiosis: one cell divides twice to form four daughter cells. The four ce3lls have half the number of
chromosomes of the parent cell. They are haploid.




There are nine stages IPMAT1PMAT2:
Meiosis 1
1. Interphase
 DNA is copied resulting in two identical full sets of chromosomes
 Outside of the nucleus are two centrosomes
 Microtubules extend from the centrosomes
2. Prophase 1