Module 2 Meiosis Flashcards
Meiosis + Fertilization
Sexual Reproduction
adjoins each strand to the other non-sister chromatid
synaptonemal complex
_______ is process of pairing and binding of chromosome to its corresponding homologous chromosome forming a ________ (four chromatids)
synapsis, tetrad
process where each homologous chromosome exchange segments of alleles and is random (results in genetic variety in offsprings)
crossing over (recombination)
meiosis only produces ________: genetically different haploid cells
gametes (sperm and egg)
produces two haploid cells each containing one chromosome from the homologous pairs
Meiosis I
sister chromatids separate in both cells becoming individual chromosomes, cytokinesis of these cells produces four haploid gametes
Meiosis II
Stages of Prophase I (5)
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis
What stage of prophase meiosis I?
- replicated chromosome condense
- nuclear membrane still visible
Leptotene
What stage of prophase meiosis I?
- bivalent/tetrad forming
- synaptonemal complex forming
- beginning of synapsis
Zygotene
What stage of prophase meiosis I?
- a bivalent/tetrad has formed and crossing over has occurred
Pachytene
What stage of prophase meiosis I?
- chiasma is present
- synaptonemal complex dissociates
Diplotene
is a structure that forms between a pair of homologous chromosomes by crossover recombination and physically links the homologous chromosomes during meiosis
Chiasma
What stage of prophase meiosis I?
- nuclear membrane fragmenting
Diakinesis
- chromosome condenses
- synapsis happens forming tetrad
- crossing over / recombination
- nuclear membrane disappears
- centrioles move to opposite poles
- spindle fiber grows
Prophase I