Genetics and Development AP Biology Genetics and Development
Fertilized egg of a frog ZYGOTE Fertilized egg of a frog
Specialized Epithelial tissue See the DIFFERENT shapes?
Specialization Nervous Tissue
Morphogenesis over time Animal development Gut Cell movement Zygote (fertilized egg) Eight cells Blastula (cross section) Gastrula (cross section) Adult animal (sea star) Cell division Morphogenesis Observable cell differentiation Plant development Seed leaves Shoot apical meristem Root apical meristem Zygote (fertilized egg) Two cells Embryo inside seed Plant
Apoptosis “Programmed Cell Death… it’s in the DNA.”
Morphogenesis in Plants
Morphogenesis in Animals
Cloning of Dolly Mammary cell donor Egg cell donor Egg cell from ovary Nucleus removed Cells fused Cultured mammary cells are semistarved, arresting the cell cycle and causing dedifferentiation Nucleus from mammary cell Grown in culture Early embryo Implanted in uterus of a third sheep Surrogate mother Embryonic development Lamb (“Dolly”) genetically identical to mammary cell donor
Embryonic Stem Cells (These have pluripotential – they can become any type of cell.)
LE 21-9 Embryonic stem cells Adult stem cells Totipotent cells Pluripotent cells Cultured stem cells Different culture conditions Different types of differentiated cells Liver cells Nerve cells Blood cells
Pattern Formation for Plants
Pattern Formation
Pattern Formation
Positional Information
Maternal Effect and Zygote Polarity Animal hemisphere Point of sperm entry Animal pole Vegetal hemisphere Vegetal pole
cytoplasmic determinant . Unfertilized egg cell Sperm Molecules of another cytoplasmic determinant Molecules of a cytoplasmic determinant Nucleus Fertilization Zygote (fertilized egg) Mitotic cell division Two-celled embryo Cytoplasmic determinants in the egg
Stem cells communicating using ligand molecules . Early embryo (32 cells) Signal transduction pathway NUCLEUS Signal receptor Signal molecule (inducer) Stem cells communicating using ligand molecules
Segment Genes Adult fruit fly Fruit fly embryo (10 hours) Fly chromosome Mouse chromosomes Mouse embryo (12 days) Adult mouse
Hox Genes