1. Fundamentals of Genetics Gregor Mendel: Genetics Pioneer Genetics = study of __________. Gregor Mendel – Australian Monk Identified 7 pairs of contrasting characteristics in _______ __________. Mendel’s Experiment Developed pure strains for each of the 14 characteristics by self pollination (pollen from anther to stigma of same flower or plant) Then, cross pollinated Parent plants = P 1 generation First generation of offspring = F 1 generation Second generation of offspring = ____ generation Mendel’s Results P 1 : green pods x yellow pods ---------> all green pods (F 1 ) F 1 : green pods x green pods -------> ¾ green pods, ¼ yellow pods Mendel got the same ¾ to ¼ ratio or ____ pair of pure traits he tested genes pea plants F2F2 each

2. https://www.youtube.com/watch?v=0vAAf4g5iF 8

4. Genes and Appearance Genotype: gene combination present Example: TT, Tt, tt Phenotype: _______ __________ due to gene action Example: tall, tall, short Homozygous: both gene of pair ______________ Example: TT, tt Heterozygous: genes of pair _____________ Example: Tt Also called a hybrid Alleles: contrasting traits for the same characteristic Example: tallness and shortness Multiple Alleles: traits with more than two alleles Example: blood type (A, B, O) How many of these possible different genes can you inherit? __________________ Physical appearance chromosomes 2 (two)

5. Mendel’s Conclusions Principles of Dominance and Recessiveness = one factor in a pair may mask the other, preventing its ______________. Law of Segregation = a pair of factors is segregated, or separated during the formation of gametes Law of Independent Assortment = factors are distributed to gametes separate of other factors *Later found to be untrue where gene linkage is present Modern Look at Mendel’s Work Mendel’s factors = _______. Letters used to represent gene pairs: – Capital letters for dominant genes – Lower case letters for _________ genes Example: Tallness vs. Shortness T = tall gene t = short gene TT = _____ Tt = _____ tt = ____ expression genes recessive Tall Short