Introduction to Reproduction

Reproduction is the process of giving birth to living beings to their young ones. It is of two types: asexual and sexual reproduction.

1. Asexual Reproduction

The reproduction without the fusion of males and female's gamete is called asexual reproduction.

Features

• Only one organism is involved. There is no male and female.
• It completes in a short period of time.
• Offspring is genetically identical to the parent.
• Mitosis cell division occurs.

2. Sexual Reproduction

The reproduction by the fusion of male and female gamete is called sexual reproduction.

Features

• Both males and females are involved.
• It completes in a long period of time.
• Meiotic cell division occurs first.
• Offspring aren't genetically identical to parents.

Difference:

Asexual	Sexual
1.     Only one organism is involved.	2.     Both males and females are involved.
3.     Offsprings are genetically identical.	2. Offsprings aren’t genetically identical.
4.     It completes in a short period of time.	3. It completes in a long period of time.
5.     Mitotic cell division occurs.	4. Meiotic cell division occurs.

Male and Female: 

The organism which produces sperm is called male and which produces ovum is called female.

Unisexual Organism:

The organism that has a male and female reproductive organ in the different individuals is called a unisexual organism.

Example: human, rabbit, cow, e.t.c.

Bisexual Organism:

The organism that has male and female reproductive organs in the same individual are called bisexual organisms. They are called hermaphrodite.

Example: Hydra, Earthworm, e.t.c.

Gamete: The reproductive cell produced by the reproductive organ is called gamete. It is haploid(n) in nature.

1. Male Gamete: The reproductive cell produced by the male reproductive organ is called male gamete. It is also called sperm. It is small and active.
2. Female gamete: The reproductive cell produced by the female reproductive organ is called female gamete. It is also called an ovum. It is large and inactive.

Fertilization

The process of fusion of male and female gamete is called fertilization.

There are two types of fertilization, they are:

1. External fertilization: The fertilization in which the fusion of male and female gamete takes place outside the body of female is called external fertilization. Example: frog, fish, e.t.c.
2. Internal fertilization: The fertilization in which the fusion of male and female gamete takes place inside the body of the female is called internal fertilization. Example: dog, rabbit, crow, e.t.c.

Zygote:

The new cell formed by the fusion of male and female gamete is called a zygote. It is diploid (2n) in nature.