Question

Which of the following statement is correct for meiotic metaphase I?

• A. Bivalents are arranged at equator.
• B. Univalents are arranged at equator.
• C. Non-homologus chromosomes forms pair.
• D. Spindle fibers are attached at chromomere.

Answer 1

The correct option is A Bivalents are arranged at equator.

During metaphase I, homologous pairs move together along the metaphase plate, as kinetochore microtubules from both centrosomes attach to their respective kinetochores, the paired homologous chromosomes align along an equatorial plane that bisects the spindle, due to continuous counterbalancing forces exerted on the bivalents by the microtubules emanating from the two kinetochores of homologous chromosomes. The physical basis of the independent assortment of chromosomes is the random orientation of each bivalent along the metaphase plate, with respect to the orientation of the other bivalents along the same equatorial line