Different ways of reproducing offspring

In internal fertilization, there are three different ways in which animals usually produce their young ones which include:

Oviparity: The eggs that get fertilized are laid outside the female’s (mother) body. Nourishment to the eggs is received from the yolk. Examples of oviparous animals include amphibians, fish and all birds.

Ovoviviparity: The eggs that get fertilized are preserved and protected in the body of the female and the nourishment is received to the embryo from the yolk. The offspring are developed completely when they hatch. This is observed in some sharks, bony fish, lizards, snakes etc.

Viviparity: Here, the offspring develops and grows inside the body of the mother and the nourishment is received via the placenta. Viviparous animals include a few reptiles, most of the mammals and cartilaginous fish.

Internal Fertilization in Humans
The type of fertilization observed in humans is internal. The male inserts the sperm into the reproductive tract of the female. In the ampulla of the ovarian tube, there occurs the fusion of sperm with the egg. A zygote is formed as a result which undergoes mitosis to develop an embryo. Then the implantation of the embryo occurs into the uterus. The whole development process of the young one or child occurs inside the uterus. The child is delivered when it is developed fully. However, the risk of sexually transmitted diseases gets increased in humans due to internal fertilization. But even then, it is one of the extensively favourable methods of fertilization. The method of internal fertilization in humans is quite complicated and includes several components and steps essential to attain the final result of human life.

Advantages of Internal fertilization
Following are some of the advantages of internal fertilization:

Possibilities of the gamete fusion increases. A benefit of internal fertilization is the protection of the fertilized egg on the land from dehydration. Within the female, the embryo is isolated which restricts the young ones.

The chances of successful fertilization is more.

The probability of gamete’s dehydration decreases.

Selective mates are found.

Protection of the offspring against the predators and the outside surrounding and therefore, increases the possibilities of survival.

The egg fertilization is also enhanced by internal fertilization by a special male. Although, fewer young ones are reproduced via this process and their survival rate is higher as compared to that for the external fertilization.

Another advantage of this type of fertilization is that it can happen in a dry environment.