What triggers the completion of meiosis 2?

Fertilization and completion of meiosis. (A) Fertilization induces the transition from metaphase II to anaphase II, leading to completion of oocyte meiosis and emission of a second polar body (which usually degenerates).

What event triggers the second meiotic division of the oocyte?

Second meiotic division in female egg do not get completed before the entry of sperm. Hence, second meiotic division takes place after ovulation, inside fallopian tube. As the sperm head enters egg cytoplasm, second meiotic division proceeds to its final phase, giving out a second polar body.

What happens at the end of meiosis 2?

At the end of meiosis II, we form special sex cells called gametes. This process ensures that these gametes only contain one set of chromosomes. They get their other set of chromosomes when they are fertilized by another gamete.

What is the necessity of meiosis 2 during formation of gametes?

Because meiosis creates cells that are destined to become gametes (or reproductive cells), this reduction in chromosome number is critical — without it, the union of two gametes during fertilization would result in offspring with twice the normal number of chromosomes!

What triggers meiosis?

Hormonal stimulation of diplotene-arrested oocytes initially triggers the resumption of meiosis by activating MPF, as at the G2 to M transition of somatic cells. As in mitosis, MPF then induces chromosome condensation, nuclear envelope breakdown, and formation of the spindle.

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Where does meiosis 2 occur in oogenesis?

The final phase of oogenesis includes the second phase of meiosis (meiosis II) during which the secondary oocyte, or mature egg cell, is produced. This stage occurs after puberty. All three phases of oogenesis occur within the ovary.