Question

Spindle apparatus is formed during which stage of mitosis?

• A. Prophase
• B. Metaphase
• C. Anaphase
• D. Telophase

Answer 1

The correct option is A Prophase

The mitotic cell division is carried out in various stages. Coiling of chromatin material into distinct chromosomes is the most important event of prophase. Formation of spindle apparatus occurs during prometaphase stage. The spindle fibers attach to the centromere.

The nuclear membrane breaks apart into numerous "membrane vesicles", and the chromosomes inside form protein structures called kinetochores. Kinetochore microtubules emerging from the centrosomes at the poles (ends) of the spindle reach the chromosomes and attach to the kinetochores, throwing the chromosomes into agitated motion. Other spindle microtubules make contact with microtubules coming from the opposite pole.

So, the correct answer is option B.