Cell Cycle Flashcards
Purpose of Cell Division
- Reproduction
- Growth
- Repair damage
Cell Division for Reproduction
All cells use division to reproduce
2 kinds of reproduction:
Asexual: *1 Parent *Offspring genetically identical.
Sexual: 2 ParentsOffspring gets genetic info from both parents (each parent contributes 1 gamete)
Cell Division for Growth
Organisms grow as no. of cells increase. Size of cells DOESN’T increase.
Cell Division for Repair
Every organism needs to repair themselves to stay alive by performing cell division.
Injuries may take months to years to get repaired on the other hand, skin cells are replaced millions of times per day.
Why aren’t cells big?
If they were, chemicals, water and waste couldn’t be transported quickly. Hence, the cell can’t properly function
Diffusion
Net movement of anything from a region of higher concentration to a region of lower concentration. Solute moves
Osmosis
A process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one. Solvent moves
Cell cycle order
I, PMAT C
Interphase
Longest phase (90% time). 3 checkpoints: *G1 phase: Cell Growth *S (Synthesis) phase: Replication of DNA *G2 phase: Cell Growth
Prophase
Key word: “preparation”
- Nuclear membrane breaks down.
- Nucleolus disappears
- chromatin coils up
Metaphase
Key Word: “middle”
* Chromosomes line up in the middle
Anaphase
Key Word: “away”
- Spindle fibres contract
- Centromeres are separated
- Each Chromosome splits into 2 sister chromatids
- Moves to opposite poles
Telophase
Key Word: “Two” * Spindle fibres disappear * Nuclear membrane forms around each set of chromosomes * Nucleolus reappears Chromosomes —> chromatins
Cytokinesis
- Cytoplasm divides
* 2 Daughter cells formed
Difference between plant and animal cell cycle
Animal cells —> Cleavage Furrow
Plant Cells —> Cell Plate
