Question

Fill up the blanks in the following paragraph by selecting the correct option. During copulation (coitus), semen is released by the penis into the vagina and is called ---(i)---. The ovum released by the ovary is transported to the ---(ii)-- where ---(iii)-- takes place. During fertilisation, a sperm counts in contact with the Zona pellucida layer of the ovum and induces changes in the membrane that blocks the entry of --(iv)----. The secretions of the -(v)--- help the sperm into the cytoplasm of the ovum.

(i) fertilisation (ii) fimbriae (iii) insemination (iv) eggs (v) middle piece
(i) insemination (ii) ampullary ischemic junction (iii) fertilisation (iv) additional sperms (v) acrosome
(i) ovulation (ii) ampulla (iii) fertilisation (iv) additional sperms (v) tail
(i) parturition (ii) isthmus (iii) insemination (iv) eggs (v) acrosome

Answer 1

Hint: In humans, reproduction happens sexually. The male and female reproductive systems have their own parts which are different from each other. They perform their own functions. Human reproductive events include the development of sperms in males and ovum in females.

Complete Answer:
- The penis is the male 's external gender identity. It is made of high - grade tissue that assists in the erection of the penis to promote insemination.
- Insemination is the method of releasing semen into the vagina by the penis during copulation. The motile sperm swims easily, passes through the cervix, reaches the uterus and eventually enters the ampullary portion of the uterus called Falopian tube.
- The ovum that is produced by the ovary is also transported to the ampullary region where fertilisation is taking place. Fertilization will only happen if the ovum and sperm are transported concurrently to the ampullary region.
- That's why not most of the copulations lead to fertilisation and conception. The process of combining the sperm with the ovum is called fertilisation.
- Through fertilisation, the sperm comes into contact with the zone pellucid layer of the ovum and creates changes in the membrane that obstruct the entry of additional sperms. This means that only one sperm will fertilise the ovum.
- Secretions of the acrosome allow the sperm to reach the ova cytoplasm through the pellucid zone and the plasma membrane.

Note: There are interesting variations between reproductive events in males and females, for example, sperm formation continues even in elderly men, but ova formation ends in women around the age of fifty years.