Constitution of the United States of America (1787). Download PDF of the Constitution. The Constitution was written in the summer of 1787 in Philadelphia, Pennsylvania, by delegates from 12 states, in order to replace the Articles of Confederation with a new form of government.
Gametes have a haploid number (23). When conception occurs, a human sperm and ovum combine their chromosomes to make a zygote (fertilized egg) with 46 chromosomes. This is the same number that the parents each had in their somatic cells. In doing this, nature is acting conservatively. Each generation inherits the same number of chromosomes.
Ovulation occurs when a mature egg is released from the ovary, pushed down the fallopian tube, and available to be fertilized. The lining of the uterus has thickened to prepare for a fertilized egg. If conception does not occur, the uterine lining will be shed. The shedding of an unfertilized egg and the uterine wall occurs during menstruation. An egg lives 12-24 hours after leaving the ovary.