Birth is the only means that will preserve the human species from extinction and ensure the continuity of life. Although the processes of pregnancy and childbirth are complex, we must know and understand them because of their importance. In this process, the reproductive systems of both male and female are involved. They produce sex cells or gametes: the egg and the sperm. These systems are essential for producing new embryonic cells that are almost identical to those of the parents, but each of them differs from the others. The sperm carries half of the genetic information in the form of chromosomes and transfers it to the embryo during fertilization as well as to the egg. Sperm is produced by the male reproductive system after undergoing several phases or stages. Some organs of the male reproductive system are found inside the body (internal) and the rest are external. Sperm are formed in the testicles which also release sex hormones. Then, the sperm develop in the epididymis and stay there for a few days. After that, the sperm move to the glands and form sperm via the vas deferens. Finally, the ejaculation process that flushes sperm out of the body occurs in the penis (Steven Dowshen, 2010). In the female, the egg is considered the female gamete and it carries the other half of the genes to the embryo, as we mentioned earlier. The egg is released from the ovary and then moved to the uterus through the fallopian tubes (Mangala Telang, 2007). Sperm will enter the female reproductive system through the vagina. In the first third of the fallopian tube, fertilization can take place. In the uterus, the zygote will be implanted (Keith L. Moore, 2008). This essay will explain pregnancy, the time when the fetus begins to live and discuss some ethics...... middle of article ......eiro.RDKeith L. Moore. (2008). before we are born: the essential elements of embryology and congenital malformations. PhiladelphiaMangala Telang. (2007). Atlas of medically assisted procreation technologies. New Delhi. Ronald W. Dudek, James D. Fix. (2008). Embryology. Philadelphia Sadler, T. W. (2008). Langman's Medical Embryology. Balimore, Philadelphia: Lippincott, Williams and Wilkins. Steven Dowshen. (2010). Male reproductive system. Accessed May 2010 from http://kidshealth.org/parent/general/body_basics/male_reproductive.htmlSuzanne R Trupin. (2007). Abortion. Retrieved June 20, 2007 from http://www.emedicinehealth.com/abortion/article_em.htmYounce, A. (2005). Fetal development week by week. Retrieved January 19, 2010 from http://www.amazingpregnancy.com/pregnancy-articles/157.htmlhttp://www.innerbody.com/image/repfov.htmlhttp://www.sharedjourney.com/ivf.html