Question

Second maturation division of mammalian ovum occurs

• A. Until after sperm has penetrated ovum
• B. Until nuclei of sperm and ovum fuse
• C. In Graafian follicle soon after first maturation division
• D. Shortly after ovulation before entry into fallopian tube

Answer 1

The correct option is A Until after sperm has penetrated ovum

In females, oogenesis starts at embryonic age and forms millions of oogonia. These cells start dividing and temporarily arrested at prophase-1 called primary oocyte. these oocytes acquire granulosa cells and form primary follicles which degenerate from birth to puberty. Further, they form secondary and tertiary follicle. When tertiary follicles grow in size it completes its first meiotic division and releases first polar body and secondary oocyte. Secondary oocyte completes its second meiotic division after the entry of sperms and releases second polar body.

So, the correct option is 'Until after sperm has penetrated ovum'.