Scientific Source #134 – Medical Textbook
“The development of a human being begins with fertilization, a process by which two highly specialized cells, the spermatozoon from the male and the oocyte from the female, unite to give rise to a new organism, the zygote.” 134
134 Langman, J., Medical Embryology. 3rd edition, Baltimore: Williams and Wilkins, 1975, 3.