Question

(a) Draw an electron microscopic view of a mammalian sperm. Label any six interhal structures of the sperm, (b) What do you call the area of an ovum from where the sperm makes its entry?, (c) Name the enzyme produced by the sperm to facilitate its entry, (d) List any two events taking place in an ovum just when sperm gains entry into it., (e) How does the entry of the sperm influence cell division of the secondary oocyte?

Answer 1

(b) The sperm makes its entry into the ovum by binding to the corona radiata of the egg cell and formation of the cone of attraction through which the spermatozoa enters.

(c) Hyaluronidase is the enzyme which helps the sperm to penetrate the corona radiata during fertilisation.

(d) Cortical reaction and capacitation are two events taking place in an ovum just when sperm gains entry into it.

(e) The secretions of acrosome help the sperm enter into the cytoplasm and plasma membrane of an ovum. This induces the completion of the meiotic division of secondary oocyte which is unequal and results in the formation of second polar body and ootid.