Sexual Reproduction

• Sexual reproduction requires two individuals to produce new organisms of the same type
• Male reproductive system:

  • testis/testes - Function: to produce sperms
  • scrotum - Function: to protect testes
• Female reproductive system: Ovaries, oviduct (Fallopian tube), uterus, vagina
• Female:

  1. After puberty, egg cells start to develop in ovaries
  2. Egg cells are released to oviduct
  3. Egg cells are swept to uterus by cilia (the hairs lined on the inner wall of the oviduct)
• Male:

  1. Sperm cell produced in testes
  2. Released to sperm ducts
  3. Leave the body through urethra
• Fertilisation at oviduct (fusion of nucleus of a sperm cell & nucleus of an ovum):

  1. The formation of zygote (one-cell, diploid)
  2. Zygote develop into embryo by cell division at oviduct
  3. Embryo implants at uterus wall
• Semen - Sperm cells + fluids produced by glands
• Amniotic fluid - cushions foetus from external shocks
• Placenta - site of exchange of materials (Mom -> foetus: nutrients, oxygen, foetus -> mom: waste products, carbon dioxide)
• cervix - the muscle of the lower end of the uterus; holds the baby in place during pregnancy
• zygote - fertilised, single cell
• Puberty:

  Physical and emotional changes in the body
• Male:

  testosterone hormone:

  • Voice becomes deeper
  • Hair growth (pubic, leg, facial, armpit, chest)
  • Acne
  • Active oil glands
  • Height/growth spurt
  • Muscle mass
• Female:

  Oestrogen & Progesterone hormones (Oestrogen: regulate menstrual cycle) & (Progesterone: maintain the uterus lining thickened by oestrogen):

  • Pubic/armpit hair
  • Pelvis enlarging
  • Breast growth
  • Growth spurt
  • Acne
  • Active oil glands activity