A. Definition: the union of the sperm and the mature ovum in the outer third or outer half of the Fallopian tube.
B. General considerations:
1. Normal amount of semen per ejaculation = 3 – 5 cc = 1 teaspoon
2. Number of sperms in an ejaculate = 120 – 150 million/cc
3. Mature ovum is capable of being fertilized for 12-24 hours after ovulation. Sperms are capable of fertilizing even for 3-4 days after ejaculation
4. Normal life span of sperms = 7 days
5. Sperms, once deposited in the vagina, will generally reach the cervix within 90 seconds after deposition.
6. Reproductive cells, during gametogenosis, divide by meiosis (haploid number of daughter cells); therefore, they contain only 23 chromosomes (the rest of the body cells have 46 chromosomes). Sperms have 22 autosomes and 1 X sex chromosome or 1 Y sex chromosome; ova contain 22 autosomes and 1 X sex chromosome. The union of an X-carrying sperm and a mature ovum results in a baby girl (XX); the union of a Y-carrying sperm and a mature ovum results in a baby boy (XY). Important: Only fathers determine the sex of their children
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