“The fertilized egg cell—or zygote—contains nuclear material from both parents. It marks the beginning of the life of a new human being and is a useful focal point for presenting all the diverse aspects of organic reproduction.” 123
123 Simpson, G. & Beck, W., Life: An Introduction to Biology 139 (2d ed. 1965) (cited in The Human Life Bill: Report on S. 158 Before the Subcommittee on Separation of Powers of the Senate Committee on the Judiciary, 97th Cong., 1st Sess. (1981), p. 9).