Question

Oocyte is liberated from ovary under the influence of LH, after completing

• A. Meiosis I before completion of meiosis II
• B. Meiosis I after release of polar body
• C. Meiosis and before liberating polar bodies
  
• D. Meiosis I and before liberating polar bodies
  

Answer 1

The correct option is B

Meiosis I after release of polar body

Oogenesis
Oogenesis is the process of formation of mature female gametes from oogonia. It involves meiosis.

First meiosis
During oogenesis, oogonia undergo meiosis I but get arrested at prophase I and form primary oocytes. The primary oocyte completes meiosis I at puberty. These primary oocytes develop into primary follicles.

Meiosis in primary oocyte at puberty
During puberty, the primary follicles gradually develop into tertiary follicles. At this stage, the primary oocyte completes the first meiotic division and forms a secondary oocyte and the first polar body.
It is released from the ovary at the secondary oocyte stage which is arrested at the metaphase II stage.

Second meiosis
The secondary oocyte begins meiosis II and is arrested in the metaphase of meiosis II. It is ovulated in this stage from the Graffian follicle. But during the time of fertilisation, that is, when the sperm head penetrates the ovum, it completes meiosis II and forms the ovum and second polar body.

Final answer
(D) Meiosis I after the release of polar body