18 public questions tagged with this topic.
During zygotene, homologous chromosomes start pairing, a process called synapsis, forming bivalents. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Biology Textbook for Class XI and XII (Botany section), Chapter: Biology - Botany portion covering relevant concept, Topic: Plant structure, physiology and applications.
Pachytene represents longest stable meiotic prophase stage where fully synapsed bivalents thicken and crossing over implemented. Molecular hallmark is homology-directed repair of programmed double-strand breaks introduced by Spo11 topoisomerase-like transesterase in leptotene that generates 3 prime single-strand overhangs via MRE11-mediated resection. Overhangs invade homologous duplex mediated by meiosis-specific recombinases DMC1 and RAD51, forming D-loop intermediates. Decision between non-crossover and crossover fate controlled by ZMM proteins MSH4-MSH5 heterodimer stabilizing joint molecu
Ref: Hunter, Cold Spring Harb Perspect Biol 2015, Meiotic Recombination in Pachytene. Alberts 7th ed., Chapter 21.
Prophase of meiosis I is extended into five substages to accomplish pairing, synapsis, and recombination unique to germ cells. Leptotene initiates with chromosome condensation into thin threads and formation of axial elements along each chromatid containing cohesin Rec8 and HORMA proteins. Zygotene marks onset of homologous pairing facilitated by telomere bouquet clustering at nuclear envelope driven by cytoskeletal forces and homology search mediated by DMC1 recombinase. Synaptonemal complex assembly begins in zygotene: lateral elements SYCP2 and SYCP3 polymerize along axes, transverse filame
Ref: Page & Hawley, Annu Rev Cell Dev Biol 2004, Meiotic Synapsis. Alberts 7th ed., Chapter 21, Meiosis I Prophase.
Synapsis occurs during zygotene, where homologous chromosomes pair up and form synaptonemal complexes.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
Synapsis occurs during zygotene, where homologous chromosomes pair up and form synaptonemal complexes.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
During zygotene, homologous chromosomes start pairing, a process called synapsis, forming bivalents.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
During zygotene, homologous chromosomes start pairing, a process called synapsis, forming bivalents.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
During zygotene, homologous chromosomes pair up in a process called synapsis.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
During zygotene, homologous chromosomes pair up in a process called synapsis.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
Chromosomes condense during prophase I of meiosis.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
Chromosomes condense during prophase I of meiosis.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
Crossing over occurs in the pachytene stage, not in zygotene.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
