cell cycle. meiosis. mitosis

What are the different phases of interphase?

G1 phase - cell growth

S phase - DNA synthesis occurs - replication of genetic material

G2 phase - cell prepares for division

Describe the three checkpoints of the cell cycle

G1 checkpoint - assesses cell size, nutrients and DNA

G checkpoint - ensures DNA replication is complete and checks for DNA damage

Mitotic checkpoint - monitors chromosome attachment to spindle fibres

What do cyclins/CDKs and tumor suppressors each do?

CDKs - proteins that regulate the progression of the cell cycle

Tumor suppressors - inhibit cell cycle progression

What is amitosis?

Simple form of mitosis - usually in single celled organisms

• no nuclear division

• No spindle formation

• No chromosome condensation

Describe the WHOLE process of meiosis I

• PI - chromosomes condense. Homologous form tetrads. Crossing over

• MI - tetrads align in middle. Independent assortment

• AI - homologous chromosomes separate

• TI - chromosomes arrive at poles, cytokinesis leading to two haploid daughter cells

Describe the WHOLE of meiosis II

PII - new spindle apparatus forms in each haploid cell

MII - chromosomes align

AII - sister chromatids separate to opposite poles of cell

TII - four haploid daughter cells