Question

What is meant by the terms ‘internal fertilization and ‘external fertilisation’? Explain with example.

Answer 1

Answer:

External fertilization is a mode of reproduction in which a male organism's sperm fertilizes a female organism's egg outside of the female's body. It is contrasted with internal fertilization, in which sperm are introduced via insemination and then combine with an egg inside the body of a female organism.

Answer 2

Internal fertilisation:

• The process of fusion of female and male gamete taking place inside animals is called internal fertilisation.
• The male gamete is settled inside female gamete.
• Very small number of gametes are released.
• There are three types of internal fertilisation namely oviparity, viviparity, ovoviviparity.
• Here, large contribution is made by female organisms.
• For example, humans undergo intercourse and fertilisation to form zygote. Later, it forms embryo and later, fetus. Females of human beings give birth to babies through vagina.

External fertilisation:

• The process of fusion of female and male gamete taking place outside animals is called external fertilisation.
• Both gametes are released into the environment.
• Large number of gametes are released.
• Here, the offspring survives in moisten and wet area.
• In frogs, the eggs and sperms are laid in moist area. The fertilisation takes place outside body and form zygote and develops into individual.