Friday 29 June 2012

Reproduction in Organisms-Events in Sexual Reproduction

Events in Sexual Reproduction


1. Pre-Fertilization events.
2. Fertilization.
3. Post -Fertilization events.

Pre-Fertilization events.

Gamatogenesis & Gamete transfer.
Gamatogenesis: It is the process of formation of 2 type of gametes.ie, male & Female gametes.
Male gamete is called sperm.
Female gamete is called Egg or Ovum.

Then Gametes transfer through sexual copulation or contact.

Homogametes/Isogametes And Heterogametes.

Homogametes

The male and female gametes are similar.Eg: Cladophora.

Heterogametes.

The male and female gametes are dissimilar.Eg: Egg and sperm in humans.and Fucus in algae.

Sexuality in organisms


Self Fertilization
The fusion of male and female gametes from the same hermaphrodate individual.

Some questions:

Prepare note on hermaphroditism in tapeworms and earthworms
.
Tapeworms-self fertilization.
The sperm produced in the testis of one individual can fertilise the egg produced by the same individual
.
In Earthworms-Cross fertilization.
The sperm of one individual fertilise the egg of another individual.

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