Warm Up With your partner, define genotype and phenotype.

Predicting Genetic Outcomes TEK 6B: Predict possible outcomes of various genetic combinations such as monohybrid crosses, di hybrid crosses, and non Mendelian inheritance. Trait – A particular characteristic that can vary from one individual to another. Ex: hair color Alleles - Different forms of one gene Ex: Brown, red, or blond hair are all different forms the hair color gene

Rule of Dominance Dominant gene: Always expressed if present for a trait Represented by a capital letter; “B” is for brown eyes. A brown-eyed organism could be BB or Bb to be dominant. The B for Brown eyes overpowers the b for blue eyes and so the organism displays the Brown eye trait. Recessive gene: Only expressed if two alleles are present for that trait Represented by a lowercase letter. “b” is for blue eyes. Organism must have genes bb to have blue eyes.

Homozygous vs. Heterozygous Homozygous: Organisms have 2 identical (same) alleles for a trait BB is homozygous dominant for brown eyes bb is homozygous recessive for blue eyes Heterozygous: Organisms have 2 (different) alleles for a trait Bb is heterozygous for brown eyes

Phenotypes and Genotypes Genotype: (genes) the genetic makeup or combination of 2 alleles (1 from mom & 1 from dad) Ex. BB, Bb, bb Phenotype: physical characteristics of the trait Ex. Brown hair, blue eyes (what you see) Genotype - always use the letter of the dominant trait first. Ex. Straight hair is dominant to curly hair Straight hair is dominant = capitol S Curly hair is recessive = lowercase s Genotype for straight hair = SS or Ss Genotype for curly hair = ss

Monohybrid Dihybrid Cross involving two traits. Mendelian Genetics Monohybrid Dihybrid Cross involving two traits. Cross involving a single trait. Bb x Bb RrYy X RrYy Phenotypic Ratio: 3 purple : 1 white Genotypic Ratio: 1BB : 2Bb : 1bb

Incomplete Dominance Codominance Non Mendelian Genetics Incomplete Dominance Codominance The trait does not have a completely dominant allele, and a cross between organisms with two different phenotypes results in a third phenotype. Heterozygous offspring display a third phenotype that is a blending of the parental traits Ex: Red (RR) x White (WW) Offspring: Pink (RW) The trait does not have only one dominant allele, but has two or more dominant alleles. When both are present, the individual displays both traits at the same time. Parents: Red (RR) x Blue (BB) Heterozygous Offspring: RB – red and blue striped

Multiple Alleles Non Mendelian Genetics There are four different phenotype blood groups: A, B, O, & AB They are produced by three different alleles: A, B, and O Which ones are homozygous? heterozygous? Phenotype All Genotypes Possible Type A (Dominant) IAIA (AA), IAi (AO) Type B (Dominant) IBIB (BB), IBi (BO) Type AB (Codominant) IAIB (AB) Type O (recessive) ii (OO)

Sex- Linked Traits Non Mendelian Genetics Inheriting sex-linked traits Genes located on the sex chromosomes are called sex-linked traits Because the Y chromosome is small it carries few genes, along with the male determinant sex gene. Ex. A woman who is heterozygous (a carrier) for hemophilia marries a normal man:

Folder Activity You will complete the activities in the folder with your partner. You should be using this opportunity to discuss the information and teach each other. After you finish the folder activity you will take a QR quiz over the information.

QR Quiz https://forms.office.com/Pages/ResponsePage.aspx?id=I5vQr0Sinky_OveSfD0RniqO1o4N6JhGo0UZldGCtsZUNUVWTkszWjdJV1NVMVBQNFVHUlRTVldORi4u