61.   That is also about the time a fertilized human egg implants on the uterine wall, West said.

62.   The agency considers morning-after pills a form of contraception since they block the fertilized egg from implanting into the uterine wall.

63.   The cells at the center of the current debate come from couples who sought treatment at fertility clinics and donated their frozen surplus fertilized eggs for research.

64.   The cells can morph into any type of cell, just as they do when a baby develops in the womb from a fertilized egg.

65.   The drug blocks the secretion of the hormone progesterone, which prepares the lining of the uterus for a fertilized egg.

66.   The current debate centers on the fertilized egg four days after conception when it becomes a mass of several dozen cells called the blastocyst.

67.   The fertilized eggs did fine, continuing to develop during the flight.

68.   The four female newts were given hormones to release fertilized eggs before and just after Columbia launched.

69.   The embryos, a few days past the fertilized egg stage, are destroyed in the process.