Cell Division Rubie Maranan-Causaren
The cell cycle.
Interphase Cell cycle
Karyokinesis Meiosis Cytokinesis
• • • •
Nucleus Nuclear membrane Nucleoli Chromatin network
Figure 9 9.3 3
onion root tip p
centrioles ti l
Figure 6.3. Mitosis. This type of nuclear division ensures that each daugther cell has same chromosomal number (diploid=2n) as that of the parent cell.
Film clip Film clip2
“synapsis and crossing over”
“rough rough pairing pairing” (yolked threads) (Thin threads)
Figure 6.4. Meiosis. A diagrammatic representation of the major events occurring during meiosis (example in a male animal with a diploid number of 4).
Figure 10 10.1 1
Chiasma and crossing over
How meiosis works Stages of meiosis Random orientation of chromosomes spermatogenesis
Meiosis vs. mitosis
C it i Criteria Kinds of cells no. of division/s per cycle no. off daughter d ht cells ll formed f d per cycle l chromosome no. of daughter cells progeny/daughter cells ti off cycle time l uses
Mitosis Mit i somatic cells one t two diploid (2n) genetically identical th throughout h t life lif growth, repair, and asexual reproduction
Meiosis M i i gametes (egg and sperm) two f four haploid (n) genetically different completed l t d after ft sexuall maturity (in humans) sexual reproduction, generating new gene combinations
Figure 10 10.8 8