Different types of Fertilisation
What fertilisation is:
Fertilisation is: The Fusion of a sperm cell and an egg cell to form a diploid zygote.
The Different types of fertilisation:
External Fertilisation
Internal Fertilisation
External Fertilisation:
The sperm fertilises the egg outside the body of the female, usually in water.
Advantages
Water prevents the eggs from dying out and allows the sperm to swim towards the
egg.
Disadvantages
Requires water for fertilisation to take place.
Not all fertilised eggs will survive.
Internal Fertilisation
The male deposits its sperm inside the reproductive organs of the female and fertilisation
occurs inside the female reproductive organs.
Advantages
Allows terrestrial animals to reproduce in a dry environment without the need for
water. Internal fertilisation is more certain than external fertilisation.
, Disadvantage
Less chance of fertilisation taking place.
Complication of fertilisation can occur during interphase I.
Once and egg is cell has been successfully fertilised. There are three possible ways in which
the needs of the developing embryo can be met. Namely through: Ovipary, Vivipary,
Ovovivipary.
Ovipary
Animals that lay eggs fall under this category.
-Eggs are laid and hatching takes place outside the mother’s body.
Advantage
Egg provides nutrition for the developing embryo and protects the embryo. A shelled
egg frees these animals from the need to reproduce in water.
Vivipary
Refers to animals that develop inside the mother.
-The young develop inside the uterus of the mother after the eggs are fertilised internally.
Advantage
More efficient development of the embryo as nutrients are received for a longer
period from the mother’s blood through a placenta. Embryo is protected in the body
of the mother.
Ovovivipary
Eggs that are produced and fertilised internally.
-Young develop from eggs that are fertilised internally and retained within the mother’s body
after fertilisation until they hatch.
What fertilisation is:
Fertilisation is: The Fusion of a sperm cell and an egg cell to form a diploid zygote.
The Different types of fertilisation:
External Fertilisation
Internal Fertilisation
External Fertilisation:
The sperm fertilises the egg outside the body of the female, usually in water.
Advantages
Water prevents the eggs from dying out and allows the sperm to swim towards the
egg.
Disadvantages
Requires water for fertilisation to take place.
Not all fertilised eggs will survive.
Internal Fertilisation
The male deposits its sperm inside the reproductive organs of the female and fertilisation
occurs inside the female reproductive organs.
Advantages
Allows terrestrial animals to reproduce in a dry environment without the need for
water. Internal fertilisation is more certain than external fertilisation.
, Disadvantage
Less chance of fertilisation taking place.
Complication of fertilisation can occur during interphase I.
Once and egg is cell has been successfully fertilised. There are three possible ways in which
the needs of the developing embryo can be met. Namely through: Ovipary, Vivipary,
Ovovivipary.
Ovipary
Animals that lay eggs fall under this category.
-Eggs are laid and hatching takes place outside the mother’s body.
Advantage
Egg provides nutrition for the developing embryo and protects the embryo. A shelled
egg frees these animals from the need to reproduce in water.
Vivipary
Refers to animals that develop inside the mother.
-The young develop inside the uterus of the mother after the eggs are fertilised internally.
Advantage
More efficient development of the embryo as nutrients are received for a longer
period from the mother’s blood through a placenta. Embryo is protected in the body
of the mother.
Ovovivipary
Eggs that are produced and fertilised internally.
-Young develop from eggs that are fertilised internally and retained within the mother’s body
after fertilisation until they hatch.
