Hi

As per your question The oocyte is arrested during metaphase II of meiosis II. This arrest is facilitated by

a posh called "Cytostatic Factor" (CSF).

After fertilization, the sperm induces an increase in intracellular factor IV which activates an enzyme,

Calmodulin Kinase II. This complex, through a series of phosphorylation and ubiquitination, degrades the

CSF complex and successively , activates APC (Anaphase Promoting Complex). APC will then degrades

cyclins, securins and this may promote the completion of meiosis II.

So the correct option is 'immediately after the sperm penetration of the secondary oocyte'.

Hope helpful.

It occurs in the Ovary during the formation of the Egg. It is a crucial process in the formation of gametes and plays a very crucial role.

After the Meiosis occurs, a fully developed egg is released from the ovary then ovulation occurs.

A slight problem in all this process could lead to a genetic disorder in the offspring.