Which statement correctly describes oogenesis?

Which statement correctly describes oogenesis?

• A. Mitosis produces primary oocytes that mature during puberty.
• B. Oogenesis occurs only after fertilization.
• C. Spermatogenesis occurs in ovaries.
• D. Meiosis I (secondary oocyte and first polar body) followed by meiosis II (haploid ootid and second polar bodies) in females

Answer: (D)

Oogenesis uses two sequential meiotic divisions that produce a single large egg cell and small polar bodies, with the division pattern that preserves most cytoplasm for the future ovum. In the first meiotic division, the primary oocyte gives rise to a secondary oocyte and a first polar body. The secondary oocyte then begins the second division but is arrested at metaphase II until fertilization occurs. If fertilization happens, meiosis II completes, creating a haploid product (often described as an ootid before maturation) and a second polar body. This sequence explains why one functional gamete is formed per cycle and why polar bodies are produced as byproducts of the asymmetrical divisions. The other statements don’t fit: oogenesis does not rely on mitosis to form primary oocytes, it begins before fertilization, and spermatogenesis occurs in the testes rather than the ovaries.

Oogenesis uses two sequential meiotic divisions that produce a single large egg cell and small polar bodies, with the division pattern that preserves most cytoplasm for the future ovum. In the first meiotic division, the primary oocyte gives rise to a secondary oocyte and a first polar body. The secondary oocyte then begins the second division but is arrested at metaphase II until fertilization occurs. If fertilization happens, meiosis II completes, creating a haploid product (often described as an ootid before maturation) and a second polar body. This sequence explains why one functional gamete is formed per cycle and why polar bodies are produced as byproducts of the asymmetrical divisions. The other statements don’t fit: oogenesis does not rely on mitosis to form primary oocytes, it begins before fertilization, and spermatogenesis occurs in the testes rather than the ovaries.