Question

Which of the following is correct about internal fertilization and external fertilization?
A. Internal fertilization – Fertilization inside the female body, External fertilization – Fertilization outside the female body.
B. Internal fertilization – Fertilization outside the female body, External fertilization – Fertilization inside the female body.
C. Internal fertilization – Chances of the survival of the offspring are more, External fertilization – Chances of survival of the offspring are less.
D. Both A and C.

Answer 1

Fertilization is the process of the fusion of the male and the female gametes to form the zygote. It is a method of sexual reproduction. Fertilization is usually of two kinds, namely external and internal fertilization.

Complete answer:

1. Internal fertilization –
   Internal fertilization is the type of fertilization that takes place inside the female body. The male gametes are released into the female body during the time of sexual reproduction where they fuse to form the zygote. The development of the baby occurs inside the female body only though it is not necessary in all cases. Due to this reason, they have better chances of survival as the mother’s body protects them. Internal fertilization is a characteristic of various animals across different phyla. It is also seen in mammals and humans.
2. External fertilization –
   External fertilization is the type of fertilization that takes place outside the female body. The male and the female gametes are released outside the female body where they fuse to form the zygote. Usually, the gametes are released in the water where they swim to each other and form the zygote. The development of the baby occurs inside fused eggs. Due to this reason, they have lesser chances of survival as there is a constant threat of predators and other animals feeding on the eggs. External fertilization is a characteristic of various animals across different phyla. It is also seen in amphibians and frogs.
   Thus, based on the above information we can conclude that the pairs, Internal fertilization – Fertilization inside the female body, External fertilization – Fertilization outside the female body, and Internal fertilization – Chances of the survival of the offspring are more, External fertilization – Chances of survival of the offspring are less are the correct pairs about internal fertilization and external fertilization.

Hence, the correct answer is option (D).

Note: In-vitro fertilization should not be confused with external fertilization. In-vitro fertilization is an experimental and artificial technique where the eggs and the sperms are fused in a petri-dish and the zygote is placed inside the uterus.