Directions: Use the Punnett Squares Provided to Answer the Following Questions

Punnett Squares

Directions: Use the punnett squares provided to answer the following questions.

  1. Perform a cross between 2 heterozygous (Bb) parents
  1. Perform a cross between a homozygous dominant (BB) parent and a heterozygous (Bb) parent.
  1. Dominant T allele produces tall phenotype, homozygous recessive (tt) produces short phenotype. Perform a cross between homozygous recessive (tt) and homozygous dominant (TT) parents.
  1. Let’s say that in seals, the gene for the length of the whiskers has two alleles. The dominant allele (L) codes for long whiskers and the recessive allele (l) codes for short whiskers.
  2. What percentage of offspring would be expected to have short whiskers from the cross of two long whiskered seals, one that is homozygous dominant and one that is heterozygous?
  3. If one parent seal is pure long whiskered and the other is short whiskered, what percent of off spring would have short whiskers?

5.  In a certain species of mouse, pointed ears are dominant over round ears. Predict the genotypes and phenotypes of a cross between two heterozygous pointed-eared mice.

6.  In a certain species of dog, a black nose is dominant over a pink nose. Predict the genotypes and phenotypes of a cross between a homozygous dominant male dog and a homozygous recessive female.

  1. In purple people eaters, one-horn is dominant and no horns is recessive. Draw a Punnett square showing the cross of a purple people eater that is heterozygous for horns with a purple people eater that does not have horns. Summarize the genotypes and phenotypes of the possible offspring.
  1. A green-leafed luboplant (this is made up) is crossed with a luboplant with yellow-striped leaves. The cross produces 185 green-leafed luboplants. Summarize the genotypes and phenotypes of the offspring that would be produced by crossing two of the green-leafed luboplants obtained from the initial parent plants.
  1. Mendel found that crossing wrinkle-seeded plants with pure round-seeded plants produced only round-seeded plants. What genotypic and phenotypic ratios can be expected from a cross of a wrinkle-seeded plant and a plant heterozygous for this trait. (seed appearance)?
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