Meiosis Flashcards
Interphase
G1 (Gap Phase 1)
- new cell
- growth and metabolism
Interphase
S (Synthesis Phase)
- DNA is duplicated (DNA Replication)
Interphase
G2 (Gap Phase 2)
- growth and metabolism
- preparations for cell division
Meiosis 1 = “First Meiotic Division” (all diploids)
Prophase 1
- DNA condenses
- nucleoli disappear
- centrosomes (MTOCs) move to opposite sides of cell
- formation of Mitotic Spindle
- homologous chromosomes pair up = synapsis
- chromosome “arms” overlap and connect at chiasmata
- joined homologous chromosome pairs = tetrads
- nuclear membrane breaks down
- microtubules attach to “outside” kinetochores of tetrads
Meiosis 1 = “First Meiotic Division” (all diploids)
Metaphase 1
- tetrads line up at metaphase plate
note: 23 for human cells, 2 sets of functional DNA
Meiosis 1 = “First Meiotic Division” (all diploids)
Anaphase 1
- tetrads come apart - homologous chromosomes separate
- duplicated chromosomes move apart to opposite ends of cell
Meiosis 1 = “First Meiotic Division” (all diploids)
Telophase 1
- nuclear membrane reforms temporarily
- DNA uncondenses
Meiosis 1 = “First Meiotic Division” (all diploids)
Cytokinesis
- division of cytoplasm
Meiosis 2 = “Second Meiotic Division” (all haploids)
Prophase 2
- DNA condenses
- centrosomes (MTOCs) move to opposite ends of the cell
- formation of the mitotic spindle
- nuclear membrane breaks down
- microtubules attach to kinetochores at centromere region
Meiosis 2 = “Second Meiotic Division” (all haploids)
Metaphase 2
- duplicated chromosomes line up at metaphase plate
Meiosis 2 = “Second Meiotic Division” (all haploids)
Anaphase 2
- duplicated chromosomes seperate at centromere
- unduplicated chromosomes move apart to opposite ends of cell
Meiosis 2 = “Second Meiotic Division” (all haploids)
Telophase 2
- nuclear membrane reforms
- DNA uncondenses
(note: each cell contains 23 pieces of DNA info)
