At ovulation, the secondary oocyte completes meiosis II if what occurs?

At ovulation, the secondary oocyte completes meiosis II if what occurs?

• A. Fertilization takes place
• B. It is selected for ovulation
• C. It undergoes cleavage
• D. No fertilization occurs

Answer: (A)

At ovulation, the secondary oocyte completes meiosis II only if fertilization takes place. This process involves the secondary oocyte being briefly arrested in metaphase II of meiosis until a sperm cell successfully penetrates and fertilizes it. Once fertilization occurs, the completion of meiosis II is triggered, leading to the formation of a mature ovum and the second polar body. This phenomenon highlights the dependence of the secondary oocyte's meiotic completion on the presence of a sperm, underscoring the intricate interplay between gametes during reproduction. The choice related to being selected for ovulation pertains to the maturation of the follicle but does not influence the meiotic process directly. Similarly, cleavage refers to the division of the fertilized egg after fertilization, occurring post-meiosis completion. Lastly, if no fertilization occurs, the secondary oocyte will not complete meiosis II and will eventually degenerate.

At ovulation, the secondary oocyte completes meiosis II only if fertilization takes place. This process involves the secondary oocyte being briefly arrested in metaphase II of meiosis until a sperm cell successfully penetrates and fertilizes it. Once fertilization occurs, the completion of meiosis II is triggered, leading to the formation of a mature ovum and the second polar body.

This phenomenon highlights the dependence of the secondary oocyte's meiotic completion on the presence of a sperm, underscoring the intricate interplay between gametes during reproduction. The choice related to being selected for ovulation pertains to the maturation of the follicle but does not influence the meiotic process directly. Similarly, cleavage refers to the division of the fertilized egg after fertilization, occurring post-meiosis completion. Lastly, if no fertilization occurs, the secondary oocyte will not complete meiosis II and will eventually degenerate.