Human Reproduction Notes ALDRO SCIENCE DEPARTMENT Asexual reproduction - Only one parent. It occurs mainly in organisms whose bodies have a simple structure. Amoeba ( animal example ) BINARY FISSION Yeast ( plant example ) BUDDING Sexual reproduction - Two parents. Parents produce Gametes [sex cells] from sex organs. At fertilisation the gametes join together to form a single cell called a Zygote. This grows and divides many times to form a new organism. Embryo - does not look like a baby. Foetus - does look like a baby. Left Kidney Male Ureter Bladder [stores urine] Sperm Duct Testis [produces sperm] Scrotum Urethra Penis Glands [producing the liquid part of the semen] Foreskin Ureter Oviduct Left Ovary Bladder [moved to one side to show the vagina] Uterus [one egg a month, alternate ovaries]. Vagina Urethra Female Human Egg X 2 Mother’s blood into the placenta . Human Sperm X 500 placenta Foetus [ Baby ] [ filled with food and oxygen for the baby] Amnion [ cushions the baby ] Mother’s blood leaving placenta [ with carbon dioxide, urea & other waste.] Umbilical cord The Human Gestation Period is 9 months [ fertilisation to birth.] Genes are the genetic code found in every organism, which determine all it’s features [hair colour, eye colour etc.] Genes are on Chromosomes [ long thin strands, made of D.N.A. ] There are normally 46 Chromosomes [23 pairs] in a human cell nucleus, but the gametes only have half [one of each pair]. Cell Nucleus One pair of chromosomes (out of 23) shown. Each section is a different gene. One came from the mother, one from the father.