The Human Genome

Human Chromosomes Pictures of the chromosomes during mitosis when they are fully condensed Cut out the pictures and group them together in pairs (karyotype)

Chromosome types… 46 chromosomes: 44 autosomes, 2 sex chromosomes Females: XX Males: XY

Normal Karyotypes

How does the organism develop? Males and females are born in roughly a 50:50 ratio because of the segregation of sex chromosomes in meiosis

How does the organism develop? Males and females are born in roughly a 50:50 ratio because of the segregation of sex chromosomes in meiosis All human egg cells (female gametes) have an X chromosome (23,X)

How does the organism develop? Males and females are born in roughly a 50:50 ratio because of the segregation of sex chromosomes in meiosis All human egg cells (female gametes) have an X chromosome (23,X) Half of all sperm cells (male gametes) carry another X chromosome (23,X) and the other half carry a Y chromosome (23,Y); making half the developing zygotes male (46,XY) and half female (46,XX)

Family History and Genetics OBJ: act as a genetic counselor to determine the probability of a couple passing a genetic condition to offspring Family History and Genetics

If only there were a chart to organize it… A pedigree is a chart that shows the relationships in a family - Squares = indicate males - Circles = indicate females Shaded square/circle = affected individual (homozygous) Clear square/circle = unaffected individual (homozygous) Half shaded = carrier (heterozygous)

If only there were a chart to organize it… Genetic counselors use these charts to determine the genotypes of family members Most human traits are almost impossible to associate with a single gene (polygenic – eye shape, ear size, etc.) Phenotype is also determined by the environment (nutrition and exercise)

Pedigrees…

Objectives SWBAT describe the experiments of Gregor Medel, which led to the development of modern genetics SWBAT define and apply the following genetic terms: homozygous, heterozygous, alleles, genotypes, phenotypes, probability, monohybrid/dihybrid, dominance/recessive, codominance, incomplete dominance, multiple alleles, polygenic traits, sex-linked traits, test cross, pedigree SWBAT list and explain Mendel’s laws of inheritance, noting the exceptions to the laws SWBAT complete punnett squares to determine genotypic and phenotypic ratios SWBAT discuss the characteristics and cause of some of the following genetic diseases and conditions: color blindness, hemophilia, male-pattern baldness, sickle cell anemia, albinism, cystic fibrosis, tay-sachs diease, huntingtin’s disease, dwarfism SWBAT act as a genetic counselor to determine the probability of a couple passing a genetic condition to offspring SWBAT analyze and address a bioethical issue regarding genetic engineering.