Cell Division Flashcards
Cell division
Set of processes a parent cell goes through to form daughter cells
Diploid
Diploid cells have 2 copies of the chromosomes/ 2 complete sets.
23 chromosome pairs (46 chromosomes)
Tetraploid
When a cell has 4 homologous sets of chromosomes
Chromosome
Section of genome that is tightly coiled.
Cell cycle
Describes the different phases a cell undergoes in life.
2 main phases: interphase & mitotic phase.
Occurs every 24-30h depending on cell
Mitosis
Occurs regularly
Results in 2 diploid daughter cells (identical to mother cell)
Part of the cell cycle (mitotic phase).
G0 phase
Interphase subphase.
The cell isn’t actively dividing, it’s just fullfiling it’s cellular duties/functions
G1 phase
Growth phase.
Cell preparing for division. Grows, lots of protein synthesis (used for ➡️) organelles duplicated.
Stimulated by growth hormones/factors
S phase
Synthesis phase. Copies of DNA are synthesises (parent cell diploid ➡️tetraploid, 2n ➡️4n). The centrosome (involved in mitosis) is duplicated..
G2 phase
Final growth push. Organelle duplication occurs. Copied dna is checked for mistakes & corrected.
Mitotic phase
Mitosis+ cytokinesis. Leads to 2 diploid daughter cells
Prophase
*Chromatin condenses into chromatids.
*Chromatids find their copy and attach at the centromere (middle of chromatids) which forms sistercromatids.
*Nuclear envelope starts dissolving
*Centrosomes (made of centrioles) move to opposite sides of cell- begin to form spindle apparatus that attaches to centromere
Metaphase
Spindle apparatus lines upp sistercromatids at equator. One chromosomes from each pair is faced towards each en of cell
Anaphase
Chromatids are pulled apart at centromere - spindle apparatus shortens it’s fibers.
Each chromosomes pulled toward opposite sides of cell
Telophase
*Chromosomes start to uncoil at the ends of the cell.
* 2 nuclear envelopes form around the 2 sets of DNA
* Spindle apparatus is broken down