Question

In which stage of meiosis, the primary oocyte is arrested?

• A. Prophase I of meiosis I
• B. Prophase II of meiosis II
• C. Metaphase I of meiosis I
• D. Anaphase I of meiosis I

Answer 1

The correct option is A Prophase I of meiosis I

The primary oocytes (2n) in female ovaries begin their meiosis in the fetal stage but become arrested in prophase I of meiosis I. When a female hits puberty these arrested primary oocytes (2n) completes meiosis I to form large secondary oocyte (n) and small first polar body(n). Meiosis I is followed by meiosis II. When a female ovulates, the secondary oocyte which is released from the ovary is in metaphase II of meiosis II. It then completes the second phase of meiosis to make a mature ovum only if fertilisation occurs.