Encyclopedia Britannica, “Pregnancy,” page 968, 15th Edition. Chicago 1974
Share on Facebook“A new individual is created when the elements of a potent sperm merge with those of a fertile ovum, or egg.”
Category: Textbooks and Scientists
Biology of Prenatal Develpment On When Human Life Begins
The Biology of Prenatal Develpment, National Geographic, 2006. (Video)
Share on Facebook“Biologically speaking, human development begins at fertilization.”
National Geographic (2005) on the Beginning of Life
In the Womb, National Geographic, 2005 (Prenatal Development Video)
Share on Facebook“The two cells gradually and gracefully become one. This is the moment of conception, when an individual’s unique set of DNA is created, a human signature that never existed before and will never be repeated.”
The Human Organism, 4th edition, On the Development of Life
DeCoursey, R.M., The Human Organism, 4th edition McGraw Hill Inc., Toronto, 1974. page 584
Share on Facebook“The zygote therefore contains a new arrangement of genes on the chromosomes never before duplicated in any other individual. The offspring destined to develop from the fertilized ovum will have a genetic constitution different from anyone else in the world.”
Science Textbook: Embryology Is the “Story of Miracles”
Thibodeau, G.A., and Anthony, C.P., Structure and Function of the Body, 8th edition, St. Louis: Times Mirror/Mosby College Publishers, St. Louis, 1988. pages 409-419
Share on Facebook“The science of the development of the individual before birth is called embryology. It is the story of miracles, describing the means by which a single microscopic cell is transformed into a complex human being. Genetically the zygote is complete. It represents a new single celled individual.”
Medical Textbook Understanding Development On the Beginning of Life
Scarr, S., Weinberg, R.A., and Levine A., Understanding Development, Harcourt Brace Jovanovich, Inc., 1986. page 86
Share on Facebook“The development of a new human being begins when a male’s sperm pierces the cell membrane of a female’s ovum, or egg….The villi become the placenta, which will nourish the developing infant for the next eight and a half months.”
The Nervous System: Circuits of Communication in the Human Body Medical Textbook on When Life Begins
Clark, J. ed., The Nervous System: Circuits of Communication in the Human Body, Torstar Books Inc., Toronto, 1985, page 99
Share on Facebook“Each human begins life as a combination of two cells, a female ovum and a much smaller male sperm. This tiny unit, no bigger than a period on this page, contains all the information needed to enable it to grow into the complex …structure of the human body. The mother has only to provide nutrition and protection.”
Textbook Lifespan Developmental, 2nd ed On When Life Begins
Turner, J.S., and Helms, D.B., Lifespan Developmental, 2nd ed., CBS College Publishing (Holt, Rhinehart, Winston), 1983, page 53
Share on Facebook“A zygote (a single fertilized egg cell) represents the onset of pregnancy and the genesis of new life.”
Foundations of Embryology. 6th edition On the Beginning of Life
Carlson, Bruce M. Patten’s Foundations of Embryology. 6th edition. New York: McGraw-Hill, 1996, p. 3
Share on Facebook“Almost all higher animals start their lives from a single cell, the fertilized ovum (zygote)… The time of fertilization represents the starting point in the life history, or ontogeny, of the individual.”
Van Nostrand’s Scientific Encyclopedia. 5th Edition On the Beginning of Life
Considine, Douglas (ed.). Van Nostrand’s Scientific Encyclopedia. 5th edition. New York: Van Nostrand Reinhold Company, 1976, p. 943
Share on Facebook“Embryo: The developing individual between the union of the germ cells and the completion of the organs which characterize its body when it becomes a separate organism…. At the moment the sperm cell of the human male meets the ovum of the female and the union results in a fertilized ovum (zygote), a new life has begun…. The term embryo covers the several stages of early development from conception to the ninth or tenth week of life.”