Mouse Genetics
Key Vocabulary Words:
Trait
Breed
Genotypes
Phenotypes
Dominant
Recessive
Homozygous
Heterozygous
Punnet Square
Part 1 Observation - Go through Observing Patterns of Inheritance portion of
the Exploration Guide.
Try to answer these questions based on your observations:
1. Which of the following is true about the genotype of the mouse shown below?
QuickTi me™ and a
TIFF ( Uncompressed) decompressor
are needed to see thi s pi ctur e.
2. Two black-fur mice are bred, and have the litter shown below. What is the most
likely explanation for the presence of the white-fur offspring?
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
3. Two mice with white fur are bred. What will be true of the offspring?
4. Which of the following is a possible litter for two heterozygous black mice?
Part 2 Draw Punnett squares for the following breeding pairs. Write down the
percentage of the phenotypes that the Punnett square predicts.
Breed a two homozygous black mice
Breed two homozygous white
Breed two heterozygous black mice
Breed a heterozygous black mouse with a
white mouse
Go back to the Explore Learning and breed each pair at least 10 times. Record the
results of the breeding pairs.
Breeding Pair
Number of Black mice
Number of White mice
Homozygous Black Mice
Homozygous White Mice
Heterozygous Black Mice
Herozygous black w/
homozygous white
Compare the results of each breeding pair with the predictions from the Punnett
squares.
1. Did the Punnett square correctly predict the outcome of each breeding pair?
Explain?
2. You take one of the mice. It’s white. Explain in your own words why the mouse is
white.