1.6 Cell Division Flashcards
Mitosis
-divides nuclei
-after interphase
-for growth
-for embryotic development
-for tissue repair
-for asexual reproduction
Interphase
-numbers of mitochondria increase
-numbers of chloroplast inrease
-synthesise cellulose for cell wall (plant)
Supercoiling Of Chromosomes
-two chromatids of each chromosome move to opposite poles of cell
-condense chromosomes (they’re too long)
Chromosome Condensation / Supercoiling
-coil DNA molecule to mae chromosome shorter and wider
-hstones and enzymes help n supercoiling
Stages Of Mitosis
1) prophase
2) metaphase
3) anaphase
4) telophase
Prophase
-supercoiling
-nucleolus breaks down
-microtubules grow from microtubule organizing center
-microtubules form needle shaped forms that travel to cell poles
-nuclear membrane breaks down
Metaphase
-microtubules attatch to centriomeres of chromosomes
-chromosomes attatch to different poles
-chromosomes remain in cell equator
Anaphase
-centromeres devide so chromatids separate
-they go to cell poles
-mitosis produces two identical nuceli
Telophase
-chromatids on poles are now chromosomes
-nuclear membrane forms around chromosomes
-chromosomes uncoil and nucleolus forms
-cell starts to divide
Cytokinesis
-after mitosis
-cell division = cytokinesis
Cyclins
-control tasks
-controls timing of cell into next stages
-bind to kinases (enzymes)
Kinases
Attatch phosphate groups to other proteins. Proteins become active and do tasks for their phase.
Types Of Cyclins
-D
-E
-A
-B
Cell Cycle Phases
-Mitosis
-G1 interphase
-S interphase
-G2 interphase
-Cytokinesis
G1 Interphase
Cellular contents (except chromosomes) are duplicated.
