A '''human embryo''' is the first stage of human developement.
A '''human embryo''' is the first stage of human developement.
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It is formed by the fusion of the male gamete (spermatozoon) and female gamete (ovum). This is called fertilization and usually occurs in the proximal portion of the female reproductive tract.
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It is formed by the fusion of the male gamete (spermatozoon or "sperm") and female gamete (ovum or "egg"). This is called fertilization and usually occurs in the proximal portion of the female reproductive tract.