How Can You Determine Parental Genotypes Based on the Characteristics of Their Offspring?

How can you determine parental genotypes based on the characteristics of their offspring?

Record Data and Observations

Part 1

1.  Record the fur color (black or brown), coat type (rough or smooth), and eye color (dark or pink) of your pet guinea pig.

Part 2

2.  Select a male and a female guinea pig. Look at the possible offspring that these two guinea pigs could produce. For each possible offspring, record the phenotype and the genotype.

3.  Based on the patterns of inheritance that you see among the offspring, describe which guinea pig traits (color: black or brown, coat: smooth or rough, and eyes: dark or pink) appear to be recessive and explain why.

4.  Based on the characteristics of your pet guinea pig, describe what you can conclude about the genotype of your guinea pig.

5.  Choose a male and a female guinea pig that you think could be the parents of your pet guinea pig. In the table below, record the genotypes of the parents, the phenotypes of their possible offspring, and the possible genotype(s) for your guinea pig. If the parent guinea pigs you selected could not be the parents of your guinea pig, write “not possible” in the last column and select a different set of possible parents.

Analyze and Conclude

6.  Identify Knowns and Unknowns Describe the method you used to identify the potential parents of your guinea pig.

7.  Analyze Data Your classmate claims that she can correctly identify the genotype of her pet guinea pig simply by looking at it. If your classmate is correct, what are the phenotype and the genotype of her guinea pig? Explain your answer.