Biology - Human Reproduction Question with Solution | TestHub

In human females, the secondary oocyte is arrested in the metaphase II stage of meiosis II before ovulation.

The completion of meiosis II occurs only when a sperm enters the secondary oocyte during fertilization.

Upon the entry of the sperm, the secondary oocyte completes its second meiotic division, resulting in the formation of a large ovum (ootid) and a small second polar body.

Therefore, the presence of the second polar body is a definitive confirmation that the process of fertilization has occurred.

Answer: $2^{nd}$ polar body