Question

............... develop between the homologous chromosomes during zygotene.

• A. Cohesion force
• B. Synaptic force
• C. Both A and B
• D. Adhesion

Answer 1

The correct option is B Synaptic force

Meiosis I is characterised by an elaborate prophase I. Prophase I comprises of substages - leptotene, zygotene, pachytene, diplotene and diakinesis. The chromosomes start tight coiling during leptotene. During zygotene, homologous chromosomes get paired. This pairing is called synapsis and occurs under the influence of synaptic force. Crossing over occurs during pachytene and the points of crossing over are visible as chiasma during diplotene. Diakinesis is the stage of terminalization of chiasma and separation of homologous chromosomes.

Thus, the correct answer is (B).