Question

Where does fertilization occur in mammals?
A. Uterus
B. Fallopian tube
C. Vagina
D. Cervix

Answer 1

It is the process of fusion of two gametes to produce a new organism similar to the parents and initiate the development of the young one. Fertilization is seen in the case of sexual reproduction. Fertilization has several processes involved with it and has been classified into two types.

Complete answer:
During the process of copulation the semen from the penis is released high up in the vagina, the process is termed insemination. The sperms are motile and they swim rapidly passing the cervix, uterus and then finally reaching the fallopian tube. Fertilization is an extremely complex process.
The fallopian tube is divided into three parts-
a. Infundibulum: this part is closer to the ovary and is funnel-shaped.
b. Fimbriae: these are present on the edges of the infundibulum and are finger-like projections that help in the collection of ovum after the process of ovulation is completed.
c. Ampulla: it is the wider part where the infundibulum opens.
d. Isthmus: it has a narrow lumen, joining the uterus.
The process of fusion of male and female gametes takes place at the ampullary region of the fallopian tube.

Hence, the correct option is (B).

Note: Fertilization can only take place if the sperm and ovum are transported simultaneously to the ampullary region. The process of fertilization leads to the formation of a diploid cell called a zygote. The fertilizations that occur somewhere other than the ampulla of fallopian tubes lead to ectopic pregnancies, which ultimately lead to the failure of the formation of a zygote.