Student Exploration: Mouse Genetics (Two Traits)
Vocabulary: allele, genotype, phenotype, probability, Punnett square
[Note to teachers and students: Thi... [Show More] s Gizmo was designed as a follow-up to the Mouse Genetics
(One Trait) Gizmo™. We recommend doing that activity before trying this one.]
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. A single coin is flipped four times. What do you think is the most likely outcome?
A. Four heads
B. Three heads, one tail
C. Two heads, two tails
D. One head, three tails
E. Four tails
F. All are equally likely
2. What do you think are the odds of getting four tails in a row? Explain your answer.
B. The odds of getting four tails in a row are ½ * ½ * ½ * ½
because every flip has an equal probability of being heads or tails. So with 4 flips you would
have a 1/16 chance.
E. Gizmo Warm-up
F. On the Mouse Genetics (Two Traits) Gizmo, drag mice into
the Parent 1 and Parent 2 spaces, and then click Breed to see
their offspring. Experiment with different combinations of parent
1. What must be true to have offspring with black fur?
I. Since black fur is dominant, the
allele for black fur must be present.
2. What must be true to have offspring with white fur? Both alleles must code for white fur
since it is a recessive trait.
3. What must be true to have offspring with black eyes? If the allele for black eyes is present,
you will have them because it is a dominant trait.
4. What must be true to have offspring with red eyes? Both alleles must code for red.
N. What must be true to have offspring with red eyes and white
fur?O. Because they both are recessive traits, there must be no
genes that code for another trait; in other words, all the genes must code for either red eyes
or white fur.P.
S. Get the Gizmo ready:
. • Click Clear.
xplo•rinTurn on Show genotype.
V. Question: What patterns appear when two traits are
1. Observe: Breed a black-fur, black-eye mouse with a white-fur, red-eye mouse. Click Breed
several times, and then drag two of the offspring into the Holding Cages below. Move the
cursor over a mouse to see its genotype, or allele combination. [Show Less]