Punnett Squares
Work the following problems. Be sure to include the genotypes of the parents, the worked Punnett square, genotypic fractions and ratios, and phenotypic fractions and ratios. 1. G = green seeds g = yellow seeds Cross a plant that is heterozygous for green seeds with a plant that is homozygous for yellow seeds. Name: ____________________________ Section: _____________ 2. H = Stripes h = Patches B = Black b = Orange Cross an orange cat that is heterozygous for stripes with a heterozygous black cat that has patches. Print off and complete the Punnett square homework (Ch12 Punnett Square HW), then answer the following questions. Note: fractions with a numerator of “0” have a denominator equal to the number of boxes in the Punnett square. Monohybrid Punnett Square: 1) The genotype of the first parent is and the genotype of the second parent is . 2) The possible genotypes are (list all 3, separated by colons), the genotypic ratios are (separated by colons), and the genotypic fractions are (separated by colons and in simplest form). 3) The possible phenotypes are and , the phenotypic ratios are (separated by colons), and the phenotypic fractions are (separated by colons and in simplest form). Dihybrid Punnett Square 4) The genotype of the first parent is and the genotype of the second parent is . 5) The possible genotypes are (list all 9, separated by colons), the genotypic ratios are (separated by colons), and the genotypic fractions are (separated by colons and in simplest form). 6) The possible phenotypes are , , , and , the phenotypic ratios are (separated by colons), and the phenotypic fractions are (separated by colons and in simplest form). The phenotype associated with a(n) allele is ONLY seen if the individual does NOT have a(n) allele. Print off and complete the pedigree homework (Ch12 Pedigree HW), then answer the following questions. Pedigree #1: 1) This trait follows a inheritance pattern because individuals and in generation are and individual in generation is . 2) Individual 3 in generation IV has % chance of inheriting this trait. Pedigree #2: 3) This trait follows a inheritance pattern because individuals and in generation are and individual in generation is . 4) Individual 12 in generation II has % chance of inheriting this trait. Genetics Pedigree Homework 1) Fill in the genotypes for as many people in the pedigree as you can. (You may pick any letter to represent this trait.) 2) What pattern of inheritance does this trait f ollow (dominant, recessive, sex – linked )? How do you know? 3) What are the chances that person 3 in generation IV will get the trait?
