Reproduction in Animals

Sexual reproduction: Reproduction which begins with the fusion of male and female gamete is called Sexual reproduction.

Fertilization: Fusion of egg with sperm is called Fertilization.

Fusion of male and female gametes produce fertilize egg which is Zygote.

Fertilization which takes place inside female body is called internal fertilization.

Fertilization done by doctors, outside the body, is called In-vitro fertilization?

A layer of Jelly holds the eggs together and provides them protection.

The type of fertilization in which fusion of male and female gametes takes place outside the body of female is called External fertilization. It takes place in animals like frog, lizard, fish etc.

Internal fertilization: Human and Hen.

External fertilization: Frog and Starfish.

Zygote: Single fertilizes egg and found in oviducts.

Embryo: Ball of cells and gets embedded in the wall of uterus for development.

Zygote divides repeatedly to give ball of cell called Embryo.

The stage of embryo in which all body part can be identified is a Foetus. When the development of foetus is complete, the mother gives birth to the baby.

Human female reproductive organ:

Human male reproductive organ:

Human being gives birth to baby, they are viviparous; whereas Hen lays egg and they are oviparous.

Organisms having internal fertilization, like hen, produce one egg at a time. This is so because here there is less chance of failure of fusion between male and female gamete. After the gametes are fertilized there is just the need of development of animal in the form of egg. Frog like aquatic organisms who shows external mode of reproduction have to lay egg in hundred. The first reason behind this is the single egg is so small in size that it will not be possible to stay to definite position and which in turns make hard for sperm to found and fuse them. Whereas, when large number of eggs make them stick together this makes fertilization possible. Another reason behind this is there is a lot of organisms who feed on these eggs, so larger number of eggs gives more possibility of giving birth to young ones

The process is Fertilization.

1. A: Sperm
2. B: Nucleus
3. C: Egg

The animals which give birth to young one are called Viviparous animal. Like cow, dog etc.

Amoeba reproduce asexually through Binary fission:

The transformation of larva into adult through drastic changes is called Metamorphosis.

The developmental stage is Foetus.

Match the following:

Silkworm and Frog have young ones different from adult.

Mode of reproduction in which only single parent is involved is called asexual reproduction.

No, there is another mode of asexual reproduction apart from Budding, which is Binary fission.

The mode of asexual reproduction in which an animal reproduce itself by dividing into two individual is called Binary fission. Amoeba follows this mode for its reproduction.

In Budding new organism develops from bud, whereas, in Binary fission organism reproduce by dividing itself into two.

Human sperm:

Chickens are not actually born, they are hatched from eggs. A chicken will ovulate and lay an egg within 24 hours. The chicken will continue to lay eggs every 24-36 hours. After eggs are layed, it takes about 3 weeks for them to hatch.

Life cycle of frog: Eggs --> Early tadpole --> Late tadpole --> Adult frog

Life cycle of a butterfly: Egg--> Larva or caterpillar --> pupa --> Adult

The transformation of the larva into an adult through drastic changes is called as metamorphosis. This is the matter of contradiction that human beings undergo metamorphosis or not. Some people say humans don't go through metamorphosis. We just change size and appearance, but we are not considered to go through metamorphosis. On the other hand some people say Of course we go through metamorphosis! When you are born you are a big foot-long worm and as a young toddler you start to make a cocoon. Then, when you break out at about age 10 you are a normal looking person.

Mode of reproduction in which only single parent is involved is called asexual reproduction. Asexual reproduction can occur by any of the following ways:

Binary Fission
Budding
Sporulation
Regeneration
Parthenogenesis
Vegetative Propagation

For example: In binary fission the parent organism is replaced by two daughter organisms, because it literally divides in two.

The mode of asexual reproduction in which an animal reproduce itself by dividing into two individual is called binary fission. Amoeba follows this mode for its reproduction.

Amoeba reproduce asexually through Binary fission: