This is a priceless article from Life Site News:

LOS ANGELES, November 26, 2007 (LifeSiteNews.com) – Human beings, being mammals, do not lay eggs. This fact, known to most school children, is frequently forgotten by those in the media reporting on advancements in embryo and cloning research. The latest example of media misrepresentation on embryo research comes from Saturday’s Los Angeles Times which ran the headline, “Abortion opponents push for ‘personhood’ for eggs.”…

Despite what many refer to as the “debate” over when a human being begins to exist, the facts have been known for more than a hundred and thirty years. In 1875, the German zoologist Oskar Hertwig showed definitively that penetration of a spermatozoon into an ovum was the beginning of independent life and that the terms “conception” and “fertilization” are therefore interchangeable terms.
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Also worth looking at, this 2003 article by scientist and ethicist, Dianne Irving, “Playing God by Manipulating Man: The Facts and Frauds of Human Cloning” in which she points out:

“We are being led into ‘believing’ that what are being manipulated and dissected in petri dishes in laboratories across the world during human cloning experiments are not really innocent living human beings who will be killed in the process. Rather they are ‘just a bunch of stem cells’.”

“Human life is thus given a sacred and inviolable character, which reflects the inviolability of the Creator himself. Precisely for this reason God will severely judge every violation of the commandment ‘You shall not kill,’ the commandment which is at the basis of all life together in society. … Only Satan can delight therein: for through his envy death entered the world (Wis 2:24). He who is ‘a murderer from the beginning,’ is also ‘a liar and the father of lies’ (Jn 8:44). By deceiving man he leads him to projects of sin and death, making them appear as goals and fruits of life.” (Evangelium vitae, Par. 53)