IS2 Reproduction PPT

2,855 views

Published on

Published in: Business, Technology
  • Be the first to comment

IS2 Reproduction PPT

  1. 1. Reproduction IS2
  2. 2. Sexual Reproduction • Egg = female sex cell • Sperm = male sex cell • Sperm joins the egg = fertilization • Fertilized egg = zygote • Zygote divides many times to form the embryo and then the fetus • Cells contain nucleus where DNA is • DNA makes up chromosomes = contain all information the cell needs to work / determine your characteristics • Humans should have 46 chromosomes • Some people have more or less than this. Example: Down Syndrome = 47 chromosomes
  3. 3. Male Reproductive System • Produces sperm • Produces testosterone = controls the development of secondary sexual characteristics and the production of sperm • Testes = many tubes where sperm cells are produced • Located in scrotum = lower temperature allow sperm to develop • Sperm production starts in teenage years • Sperm travel with semen (fluid containing nutrients) • Path: testes → vas deferens → urethra (penis) • Remember: urethra = common pathway for urine AND semen
  4. 4. Female Reproductive System • Produces eggs • Nourishes a baby until birth • Ovaries = produce eggs (only 1 matures every month) • Also produce estrogen = controls the development of secondary sexual characteristics and helps prepare the uterus for the baby • Path: ovary → fallopian tube → uterus • Uterus = muscular organ where embryo develops into a baby • If the egg is not fertilized = it gets destroyed and leaves the body (along with the lining of the uterus) through the cervix and then the vagina
  5. 5. Menstrual Cycle • Every girl is born with about 400,000 undeveloped eggs in the ovaries • Only about 500 will become mature and leave (normally one per month) • Monthly cycle = egg develops + uterus prepares for the embryo • Normally takes about 28 days (could be more or less) • Ovulation = when the egg is released from ovary • Menstruation = lining of uterus + undeveloped egg leave the body through vagina • Hormones control this process Human embryo at 5-6 weeks

×