REPRODUCTION AND DEVELOPMENT Every species depends on it for survival!

Reproduction can be… Asexual *think mitosis, one parent, genetically identical! Sexual *think meiosis, two parents, variation!

All organisms… Will have either asexual or sexual reproduction Typically the less complex you are, the less variety you have (so asexual) Typically the more complex you are, the more variation you have (so sexual reproduction)

Examples of different types of asexual reproduction Binary fission (two equal cells) *ameoba Budding (unequal division) *yeast Spore formation *fungus & mold Budding (new individual on the parent) *hydra & some plants

Examples of different types of sexual reproduction Conjunction *Swapping a small portion of genetic material (paramecium) Fertilization *Joining of two cells

Cloning A type of asexual reproduction Individual is identical to one “parent” Possible in some plants (cuttings) and animals that normally reproduce sexually

Donor Nucleus Fused Cell Egg Cell Embryo Cloned Lamb Foster Mother A donor cell is taken from a sheep’s udder. Donor Nucleus These two cells are fused using an electric shock. Fused Cell The fused cell begins dividing normally. Embryo The embryo is placed in the uterus of a foster mother. Foster Mother The embryo develops normally into a lamb—Dolly Cloned Lamb Egg Cell An egg cell is taken from an adult female sheep. The nucleus of the egg cell is removed.

Mitosis No variation Occurs in all body cells Required for growth & development & repair Diploid to diploid Genetic number never varies

Meiosis Creates variation (crossing over, four cells to choose from) ONLY occurs in sex cells Required for sexual reproduction Diploid to haploid (monoploid) Genetic number cut in half (needs to be in order for the number to be restored after fertilization)

Human Male System Testes – where sperm cells mature Testosterone – hormone produced by testes

Plant male system Stamen – produces the mature sperm cell (poll) Known as pollination

Human female system Ovaries – where immature eggs are stored and mature Estrogen & progesterone – hormone produced by the ovaries Oviducts – where fertilization occurs Uterus – where placenta and embryo develop

Plant female system Pistal (stigma) – where fertilization occurs / at base is ovary Embryo is surrounded by nutrients (fruit)

Development in plants Pollination – fertilization - germination

Development in humans Gametogenesis – fertilization – zygote - embryo Differentiation Female hormonal / menstral cycle

The Menstrual Cycle Section 39-3

Application of Reproductive Technology Cloning In Vitro techniques Genetically altered plants Endangered species “help” Stem cell research Chromosome screening