8 public questions tagged with this topic.
DNA replication occurs only before meiosis I, not between meiosis I and II.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis II and Significance - Genetic Variability
DNA replication occurs only in meiosis I during the S phase, not in meiosis II, which is similar to mitosis.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis II and Significance - Genetic Variability
DNA replication occurs only in meiosis I during the S phase, not in meiosis II, which is similar to mitosis.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis II and Significance - Genetic Variability
In diplotene, homologous chromosomes start separating but remain attached at chiasmata where crossing over occurred.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
In diplotene, homologous chromosomes start separating but remain attached at chiasmata where crossing over occurred.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
During meiosis I, homologous chromosomes pair up and undergo recombination, which does not occur in mitosis.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Meiosis - Meiosis I - Leptotene Zygotene Pachytene Diplotene Diakinesis
Meiosis I produces haploid daughter cells, not diploid.
Ref: NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division Mitosis - Karyokinesis - Prophase Metaphase Anaphase Telophase
During meiosis I, homologous chromosomes normally disjoin to opposite poles at anaphase I. Nondisjunction occurs when a bivalent fails to separate, so both homologs migrate to one pole and none to the other. Consequently both secondary oocytes or spermatocytes become aneuploid. After meiosis II, sister chromatids separate normally, but all four resulting gametes carry unbalanced numbers: two gametes are n+1 disomic and two are n-1 nullisomic for that chromosome. Subsequent fertilization produces trisomic or monosomic zygotes with characteristic syndromes and developmental failure.
Ref: Griffiths et al., Introduction to Genetic Analysis, 12th ed., Chapter 3: Chromosome Segregation and Aneuploidy
