NEETBotanyCell Cycle and Cell Division
Read the following statements regarding the substages of prophase I in meiosis and select the incorrect statement.
Options
- ADuring zygotene, chromosomes start pairing together and this process of association is called synapsis.
- BCrossing over occurs between the sister chromatids of the homologous chromosomes during the pachytene stage.
- CThe beginning of diplotene is recognised by the dissolution of the synaptonemal complex.
- DDiakinesis is marked by the terminalisation of chiasmata and represents transition to metaphase.
Correct answer
B. Crossing over occurs between the sister chromatids of the homologous chromosomes during the pachytene stage.
Step-by-step solution
Crossing over is an enzyme-mediated process that involves the exchange of genetic material between two homologous chromosomes. It specifically occurs between the non-sister chromatids of the homologous chromosomes during the pachytene stage of prophase I. Therefore, the statement claiming it occurs between sister chromatids is incorrect. The other statements are factually correct as per NCERT: synapsis occurs in zygotene, the dissolution of the synaptonemal complex marks the beginning of diplotene, and diakinesis i