- Slides: 13
Karyotype • A karyotype is an x-ray picture of the chromosomes. • Scientist use this as a tool to study the chromosomes.
The sex chromosome • Humans have 46 chromosomes in each body cell • Chromosome pair #23 determines the sex of the human.
Boy or Girl? • If chromosome set #23 is…. . • XX- girl • XY- boy • Demo
Predicting the sex of the offspring. • Mom’s Genotype XX • Dad’s Genotype XY • Draw the Punnett Square.
Human Karyotype • Looking at the picture what is the sex of this offspring? • Male (XY)
Mutations • Mutations happen when there is a mistake in the DNA • Can be harmful or beneficial
Mutations Genetic Disorders Genetic Variation • Mutations can cause genetic disorders EX: Down’s Syndrome • Mutations can make new traits that help an organism better adapted to their environment
Cloning • A clone is genetically identical to its parent Plants can be cloned by cutting Animals: • Dolly the Sheep: The first clone of an adult mammal! • Pig organs
Genetic Engineering • Genes from one organism are inserted into the DNA of another organism. • Examples: • Bacteria genes put into plants to resist cold or pests • Human genes put into cows- they produce human proteins
Gene Therapy • Gene therapy: working copies of genes can be inserted to people with certain genetic disorders • Ex: Cystic Fibrosis • Still experimental
DNA Fingerprinting • DNA samples from hair, skin, or blood can be used to identify people • Produces patterned band of DNA and used to match suspects of crime
The Human Genome Project • Genome: all the DNA in one cell of an organism • Humans have about 30, 000 genes • In 2003 the DNA sequence of every gene in the human genome was identified • Help treat disease • Understand how our bodies work