Question

During the zygotene stage of prophase-I:

• A. Two homologous chromosomes attract each other
• B. Two sister chromatids of homologous chromosomes form tetrad
• C. Exchange of genetic material takes place
• D. Chiasmata formation takes place

Hint:

Think 'Zygo-' as in zygote, which involves pairing. Zygotene is the pairing (synapsis) stage of homologous chromosomes.

Answer 1

The Correct Option is A

Prophase-I of meiosis is divided into five stages. The key event of the zygotene stage is synapsis, where homologous chromosomes pair up and attract each other to form bivalents. Tetrad formation is visible in the pachytene stage, crossing over (exchange of genetic material) occurs during pachytene, and chiasmata (the physical manifestation of crossing over) become visible during the diplotene stage.