Laws of Inheritance

Genes Explanation Genes are segments of DNA that are the instructions for making a protein Genes control your inherited traits Example/Analogy You inherit the GENES for making the pigments that create your eye color

Alleles Explanation Different forms of the same gene Example/Analogy Blue, Brown, Green & Hazel are all alleles for eye color pigments

Law of Inheritance from Parents Explanation You have 2 copies of each gene You inherit 1 copy of each gene from each parent Example/Analogy Mom’s egg contained 1 copy of the gene for eye color Dad’s sperm contained 1 copy of the gene for eye color That means you INHERITED 2 COPIES of the gene B ovum b sperm

Law of Dominance Explanation Some alleles are dominant and will mask the expression of other “weaker” alleles (recessive) Example/Analogy The allele for Brown (B) eyes is Dominant to the allele for Blue eyes Blue (b) eyes is recessive BB = Brown Bb = Brown bb = blue RECESSIVE DOMINANT

Law of Independent Assortment Explanation Alleles (genes) assort randomly during meioisis This has to do with how the Homologous Chromosomes line up on the spindle Example/Analogy You can get a mix of Mom’s & Dad’s alleles in the same gamete Mom’s chromosomes don’t all have to be on the same side of the spindle

Law of Segregation Explanation During Meiosis, alleles are separated so that you only get 1 allele from each parent Example/Analogy ANAPHASE 1 = Homologous Chromosomes Separate ANAPHASE 2 = Sister Chromatids Separate Result = 1 copy of the gene in the gamete