Table of Contents
Definition of Zygote
The cell that results when a spermatozoon (sperm cell) penetrates an ovum (egg cell) during fertilization.
Each gamete (sperm and ovum) is a haploid cell; it contains one half the genetic material necessary to support life. The zygote is a diploid cell; it contains all the DNA necessary to create a new life. Fertilization typically takes place in the fallopian tube.
The zygote grows and divides as it makes its way through the fallopian tube to the uterus, a journey of about five days. When it reaches the uterus the zygote implants into the endometrium, the thick, bloodrich lining of the uterus. By the time implantation is complete the zygote has become a two-layered structure called a blastocyst.
For further discussion of the zygote within the context of the structures and functions of reproduction and sexuality, please see the overview section “The Reproductive System.”
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