Warm Up 12/22 What is an Allele? Compare Dominant vs. Recessive What is the difference between heterozygous and homozygous? Warm Up 1/9 List several environmental factors that can impact phenotype? diet, climate, illness, stress Do these factors also affect genotype? Complete Questions 8 & 9 On page 4 of the packet. Warm up 1/10 If a type O man and heterozygous type B woman have a child, what are the possible genotypes and phenotypes of the offspring? Give the percent chance the offspring are born with each genotype. Genetics Vocabulary Chapter 11 & 14.1 Genetics: Scientific study of heredity Gene: sequence of DNA that codes for a protein. Trait: specific characteristic of an individual. Allele: alternative form of a gene Dominant: an allele in a heterozygous individual that appears to be the only one affecting a trait Recessive: an allele in a heterozygous individual that does not appear to be affecting a trait Homozygous: having two identical alleles for a particular gene Heterozygous: having two different alleles for a particular gene Hybrid: Offspring of crosses between parents with different traits. Monohybrid cross: mating of two organisms that differ in only one character Dihybrid cross: mating of two organisms that differ in two characters Genotype: genetic makeup of an organism - an organism's combination of alleles Phenotype: observable traits of an organism Generations P = Parental F 1 = First Filial F 2 = Second Filial Exceptions to the principle of dominance Incomplete dominance when neither allele is dominant over the other for the same characteristic. Primrose Flowers Codominance When a single gene has more than one dominant allele. Both alleles are expressed. Codominance Polygenic Inheritance Multiple genes affect the phenotype of a trait. Four different genes affect skin color. The allele that you receive from each gene impacts the phenotype. Poly = Many Genic = Gene Many genes impact the phenotype. The Experiments of Gregor Mendel Gregor Mendel. Father of modern genetics Austrian monk Worked with garden peas because they were easy to grow and produced many offspring. Separation of alleles where each gamete receives only one allele for each gene. When does this occur? Law of Segregation Law of Independent Assortment Genes for different traits can separate independently during gamete formation. The allele for gene A doesnt affect which allele for gene B the gamete receives.