Fertilization

fertilization /fer·ti·li·za·tion/ (fer?ti-li-za´shun) impregnation; union of male and female gametes to form the diploid zygote, leading to development of a new individual.

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external fertilization  union of the gametes outside the bodies of the originating organisms, as in most fish.

internal fertilization  union of the gametes inside the body of the female, the sperm having been transferred from the body of the male by an accessory sex organ or other means.

in vitro fertilization  removal of a secondary oocyte, fertilization of it in a culture medium in the laboratory, and placement of the dividing zygote into the uterus.

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fer·til·i·za·tion (fûrtl--zshn)

n.

The union of male and female gametes to form a zygote, a process that begins with the penetration of the secondary oocyte by the spermatozoon and is completed with the fusion of the male and female pronuclei.

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Fertilization

The joining of the sperm and the egg; conception.

Mentioned in: Contraception

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fertilization

in animal reproduction, the process by which the spermatozoon unites with the ovum. By this event, also called conception, the male and female gametes unite to form a single-celled zygote. When one spermatozoon penetrates the ovum a reaction occurs which prevents any further spermatozoa entering. The nuclei of the spermatozoon and the ovum fuse in a process called syngamy and fertilization is complete.

Spermatozoa lodged in the female reproductive tract maintain their fertility for 5 days in mares, up to 90 hours in bitches and for 24 to 48 hours in cow, ewe, sow. In the female, the ovulated ovum remains viable in the tract for 12 to 18 hours.

Fertilization. By permission from Aspinall V, O'Reilly M, Introduction to Veterinary Anatomy and Physiology, Butterworth Heinemann, 2004

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in vitro fertilization

union of male and female germ cells outside the body, in an artificial environment.