BIOL 2040 Lecture Notes - Lecture 2: Synaptonemal Complex, Neurospora Crassa, Double Fertilization
Document Summary
Meiosis highlights- dna replication has already occurred prior to the onset of. Pachytene* (homologous pairing complete - recombination begins) - pairing is intimate. Metaphase 1 - homologous chromosomes pair align on spindle equator. Anaphase 1 - homologous pairs begin to pull apart (chromosomes still have 2 chromatids) Telophase 1 - pulled apart reaching poles - chromosomes less compacted. Anaphase 2 - chromatids of each chromosome pull to opposite poles. Telophase 2 - reach poles, de-condense, nuclear envelope forms. Cytokinesis leaving 4 haploid gametes (usually) - depending on the species: the laws of inheritance are driven by meiosis, mendells first law is equal segregation. Refer to figure 2-16a: pachytene spread- viewing it with electron microscopy with the tungsten stain, synaptonemal complex- has proteins in it. Structure that is intimately involved with the pairing of homologous chromosomes with pachytene: pachytene is usually quite long.
