Are you a Genetics Ninja?
Directions: Complete the sheet below. USE YOUR NOTES to help you with vocabulary.
1. A male and female bird have 4 unhatched eggs. The genes for the white female
on the left are homozygous recessive; the black male on the right is
heterozygous Use B and b for your alleles.
a. What is the genotype (alleles) of the female?
b. What is the genotype (alleles) of the male?
c. Which color is dominant, white or black? How do you know?
d. Write the phenotype of the female and the phenotype of the male below:
Female:
Male:
e. Complete the Punnett Square for this couple
(double click to open the drawing tool):
f.
If they follow the Punnett Square ratios, what will
babies in the eggs look like when they hatch?
g. If they lay one more egg, what are the chances that the chick that hatches will be black?
h. If they lay one more egg, what are the chances that the chick that hatches will be white?
the
2.
A family of fish lives in a tank in room 121. Ms. DeVaughn, while bored, decides to determine the genotypes
of the parents based on their back fins.
a. What is the dominant phenotype (Look at
what trait is most common in this family)?
b. What is the recessive phenotype?
c. What are the two possible genotypes of
each adult fish? (use F and f )
d. How many baby fish have the dominant phenotype? How many have the recessive phenotype?
e. Complete all Punnett Squares below, one each for all possible genotypes of the upper adult fish (keep
the “mom” fish on top and the “dad” fish on the side for all squares.)
2
.
1
.
f.
3
.
4
.
Which of the Punnett Squares above that is correct for the fish shown in the picture?
g. What are the genotypes of the parents?
h. Why are the other Punnett Squares not possible for this family? (assume that the offspring exactly
follow the Punnett Square ratios.)
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3. Two yetis have babies. One parent has horns, the other does not.
a. What is the dominant phenotype?
b. What is the recessive phenotype?
c. What is the genotype of the yeti parent on the left?
(Use N and n for your alleles)
d. What are the two possible genotypes of the yeti parent on the right?
e. What are the phenotypes of the yeti babies?
f.
Complete both Punnett Squares below, one each for both possible genotypes of the right adult yeti.
1
.
g.
Which of
Squares above is
family shown
2
.
the Punnett
correct for the yeti
here.
h. What are the genotypes of the parents?
i.
Why can’t the parents have a different genotype? (assume that the offspring exactly follow the Punnett
Square ratios)
4. Big and pointy back fins are dominant on this species of salamander. Could this couple have had this baby?
Explain in complete sentences (Choose your own letters to use in your Punnett Square.)
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