Mendelian Genetics Gregor Mendel “The Father of Genetics” He experimented with garden peas Easy to grow & control mating experiments observed one trait at a time Conclusions were quantitative He used math to make conclusions and develop –> Mendel’s Laws

Traits that Mendel studied:

Vocabulary : Phenotype : Appearance (ex purple flower) Genotype : Combination of alleles (Pp) Dominant : Allele that shows its phenotype (P) Recessive : Allele that has a hidden phenotype (p) Hybrid: The result of a cross (mating) between two genetically different parents. Mendel’s garden

Mendel’s Laws: 1. Genes or traits in come in pairs one from each parent 2. Law of Dominance: When a purely dominant parent (PP)is crossed with a purely recessive parent (pp) only one form of the trait will appear in the next generation. Offspring that are hybrid for a trait will have only the dominant trait in the phenotype. One factor is dominant and the other is recessive

3. The Law of Segregation: During the formation of gametes (eggs or sperm), gene pair (alleles) separate. When fertilization occurs, alleles for a trait are then "recombined" producing the genotype for the traits of the offspring 4. The Principle of Independent Assortment Alleles for different traits are distributed to sex cells (& offspring) independently of one another.

Vocabulary: Homozygous: The alleles of a given trait are the same. (exgenotype-PP or pp) Heterozygous : The alleles of a given trait are the different. (exgenotype-Pp ) ns/biology.html ->mendels exp-. animations

Genetic problems 1. In humans, brown eye color (B), is dominant over blue eye color (b). What are the phenotypes of the following genotypes? In other words, what color eyes will they have? A. BB ________________________ B. bb ________________________ C. Bb ________________________ !

Genetic problems 2. A homozygous, brown eyed man marries a blue eyed, woman. (B=brown eye; b=blue eye) Predict the possible offspring!

Genetic problems 3. A heterozygous, brown eyed woman marries a blue eyed man. (B=brown eye; b=blue eye) Predict the possible offspring!

Genetic problems 4. A heterozygous, brown eyed woman marries a heterozygous, brown eyed man. (B=brown eye; b=blue eye) Predict the possible offspring!