week 5 meiosis, mitosis and the cell cycle Flashcards
Diploid
2 sets (46)
Haploid
1 set (23)
Mitosis
IPMAT
Interphase
G1 - Growth and metabolic
S - Replication of DNA
G2 - Growth and more preparation
Prophase
Chromosomes condense and become visible
nuclear envelope breaks down
centrioles move to opposite sides of the cell
Spindle begins to form
Prometaphase
Chromosomes attach to the spindle at centromeres
Kinetochore connect chromosomes to microtubules
centrosomes form poles
Metaphase
Chromosome tightly coiled
chromatids line up on metaphase plate
each chromatid attaches to spindle fibre
Anaphase
Centromeres split in two
chromatids pulled
Telophase
chromosomes diffuse at poles
Nuclear envelope begins to reform
spindle breaks down
cytoplasm begins to divide
Cytokinesis
cytoplasm actually divides
Metaphase checkpoint
equal chromosome spindle attachment
G1 checkpoint
Cell size, nutrients, growth factors, DNA damage
G2 checkpoint
Cell size, DNA replication, DNA damage
Cyclin Protein
Activates cyclin-dependent kinases (cdks)
Cyclin-dependent kinases (cdks)
most are inactive, active with cyclins. Make a target protein more or less active.
eg, nuclear membrane breakdown or DNA replication promotion