In dogs, a black nose (A) is dominant to a light colored nose (a). Two black nosed dogs produce a litter of 4 pups. One pup has a light colored nose.  How many have black noses?

Having a pointed hairline, or Widow’s Peak, is controlled by a dominant allele, while a curved or straight hairline is recessive. Determine the phenotypes for both you and your partner.  What genotypic and phenotypic ratios would you expect in your offspring?

In African clawed toads, albino skin (a) is recessive to green skin (A). Two toads are mated. One of the parents has green skin and one has albino skin. Among the resulting offspring are twenty albinos and eighteen greens. (Show your work below!) (a) What is the genotype of the green parent? (b) What is the genotype of the albino parent? (c) What are the genotypes of the offspring? Greens Albinos (d) Did segregation of alleles occur? (e) Did independent assortment of alleles occur? (f) Explain your answers. (g) Which of Mendel’s Laws is demonstrated by this example?

If a male is homozygous dominant for a trait, that parent’s genotype might be DD. If the female is heterozygous for the same trait, her type would be Dd. a. How many genetically different sperm can the male produce? b. Using punnet square, determine the expected genotypic ratios of their offspring. c. What are the expected phenotypic ratios?