Chapter 53, Problem 3.1CT

Assume that the genes for hairline and earlobes are on different pairs of homologous chromosomes. Determine the genotypes and phenotypes of the offspring from a cross if both parents are heterozygous for both traits. (1) First determine the genotypes for each parent. (2) Determine the gametes, but remember each gamete has one allele for each trait (gametes are haploid). (3) Construct a Punnett square, with sixteen boxes, that has four different gametes from each parent along the top and the left edges. (This is an application to demonstrate Mendel’s Law of Independent Assortment.) (4) List the re suits of genotypes and phenotypes as ratio s.