Hormones Puberty Conception and Genetics Hormones Puberty Conception

Hormones Puberty Conception and Genetics

Hormones, Puberty, Conception and Genetics • Testosterone= male hormone • Estrogen & progesterone= female hormone • Maturity years occur between ages 11 -18 • Reproduction is essential for the survival of species • Reproduction is successful when one sperm fertilizes one egg(ova)

Hormones, Puberty, Conception and Genetics • Fertilization occurs when the sperm nucleus reaches the ova (egg) in the fallopian tube. Typically 9 months later a complete human is born. During that time 1 single cell has changed into trillions of cells. • If the egg is fertilized it will embed itself in the lining of the uterus. If it is not fertilized it will eventually be expelled from the body.

• Every 28 days an egg is released from one of the ovaries and travels down the fallopian tubes. The ovaries interchange (take turns) releasing eggs. • IF an egg cell and sperm cell unite the fertilized egg will embed itself in the lining of the uterus wall.

• The sperm are introduced to the female body during sexual intercourse. Out of the millions of sperm released into the vagina only a few thousand will make their way up the fallopian tubes • The sperm will meet the egg and penetrate it. If the sperm is successful the head and midpeice of the sperm will move into the egg and the tail falls off.

• When the sperm fertilizes the egg, membrane changes occur to keep all other sperm from entering the egg cell. The reason for this is only 1 sperm can unite with 1 egg because each sex cell contains ½ the number of chromosomes to the fertilized egg, which is now the zygote.

23 chromosomes from the mother + 23 chromosomes from the father __________________ 46 chromosomes for human life**

BUT WHAT ABOUT TWINS? • Twins result because: 1. Two eggs were released and two sperm fertilized the egg. 2. The fertilized egg split in two, developing 2 separate fetus.