Genetic Soduko

Purpose: Use interactive Punnett square simulations to predict possible genetic outcomes.

Directions: Go to http://www.mhhe.com/biosci/genbio/virtual_labs/BL_05/BL_05.html

1.  Select the TV and watch the tutorial.

  1. Where are the parent alleles located on a Punnett square?
  2. What do capital letters represent?
  3. What do lowercase letters represent?
  4. Describe a :
  5. Phenotype –
  6. Genotype –

2.  Select the Notebook. Complete the Punnett squares for each scenario. The “scenarios” are random (out of order). When you complete the “scenario” correctly, click the reset button and the next scenario will appear. Continue until you complete all 8 scenarios. Complete the following:

Senario # / Punnett Square / Ratio of Genotypes / Ratio of Phenotypes
/ __ /4 =____% Homozygous Dom. _____
__ /4 =____% Homozygous Rec. _____
__ /4 =____% Heterozygous _____ / __ /4 = ____% =
__ /4 = ____% =
/ __ /4 =____% Homozygous Dom. _____
__ /4 =____% Homozygous Rec. _____
__ /4 =____% Heterozygous _____ / __ /4 = ____% =
__ /4 = ____% =
/ __ /4 =____% Homozygous Dom. _____
__ /4 =____% Homozygous Rec. _____
__ /4 =____% Heterozygous _____ / __ /4 = ____% =
__ /4 = ____% =
/ __ /4 =____% Homozygous Dom. _____
__ /4 =____% Homozygous Rec. _____
__ /4 =____% Heterozygous _____ / __ /4 = ____% =
__ /4 = ____% =
Senario # / Punnett Square / Ratio of Genotypes / Ratio of Phenotypes
/ __ /4 =____% Homozygous Dom. _____
__ /4 =____% Homozygous Rec. _____
__ /4 =____% Heterozygous _____ / __ /4 = ____% =
__ /4 = ____% =
/ __ /4 =____% Homozygous Dom. _____
__ /4 =____% Homozygous Rec. _____
__ /4 =____% Heterozygous _____ / __ /4 = ____% =
__ /4 = ____% =
/ __ /4 =____% Homozygous Dom. _____
__ /4 =____% Homozygous Rec. _____
__ /4 =____% Heterozygous _____ / __ /4 = ____% =
__ /4 = ____% =
/ __ /4 =____% Homozygous Dom. _____
__ /4 =____% Homozygous Rec. _____
__ /4 =____% Heterozygous _____ / __ /4 = ____% =
__ /4 = ____% =

Conclusions:

1.  Why can’t we always predict the genotype by observing the phenotype?

2.  In which situation can we accurately predict the genotype by looking at the phenotype?

3.  Purple is dominant over pink. Cross a Homozygous pink parent with a heterozygous purple parent. Predict the genotypes and phenotypes of the offspring. Show your work using a Punnett square.

Punnett Square Genotypes Phenotypes

4.  In which type of job or career would predicting genetic outcomes be beneficial?