domingo, 5 de junio de 2011

The reproductive system

You are supposed to remember the most important about reproduction becouse you studied last year. In case you had forgotten, in this post we will begin with a review of the last year.

Reproduction is the biological process by wich new individual organism are produced. It ensures the perpetuation of the species.

There are two main types of reproduction:

Asexual reproduction requires only one parent which produces new, genetically identical living beings.
Sexual reproduction requires two parents: a male and a female. The descendants have a combination of genetic material contributed from both parents.

Sexual reproduction in animal usually requires two members of the opposite sex, a male and a female. Each member has different reproductive organs called gonads. These organs make reproductive cells called gametes.

The male gonads are the testicles and the male gametes are the spermatozoa.

The female gonads are the ovaries and the female gametes are the ova.

Fertilisation is the union of an ovum and a spermatozoon. They form a zygote.

There are two types of fertilisation:

External fertilisation when the union of the gametes occur s outside the female body. It is typical of the acuatic animal.

Internal fertilisation is the fusion of gametes which occurs inside the female body. It involves copulation, which is the transmision of spermatozoa of the male into the female reproductive system trough a copulating organ. It is typical the most of terrestrial animal.

Human living beings have this type of fertilisation . In next post we will find informatión about human reproduction.

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