Question

An egg is released and fertilised by sperm at which stage?

• A. Primary oocyte
• B. Secondary oocyte
• C. Oogonium
• D. Ovum

Answer 1

The correct option is B Secondary oocyte

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 oocyte acquires granulosa cells and forms primary follicles which degenerate from birth to puberty. Further, they form secondary and tertiary follicles. When tertiary follicle grows in size it completes its first meiotic division and releases first polar body and secondary oocyte or ovum. Secondary oocyte completes its second meiotic division after the entry of sperms and releases second polar body.

So, the correct option is 'secondary oocyte'.