Name: ______________________________________
Alien Genetics: An “Out of this World” Activity
Date: ____
Biology
Introduction
This activity is designed to reinforce your knowledge of genetics, dominant and recessive traits,
monohybrid and dihybrid crosses, Punnett Squares and Mendel’s Laws of Segregation and
Independent Assortment.
You will work in pairs. Please follow the directions carefully and answer ALL questions and complete
all data requests.
Step 1: Alien Traits
The four alien traits we will use include (a) two or four eyes, (b) scale-covered or smooth wings, (c)
curly or straight antennae and (d) bioluminescent or non-bioluminescent. The traits will be
designated as follows:




Four eyes is the dominant allele (E) and one eye is the recessive allele (e)
Scaly wings is the dominant allele (W) and non-scaly wings is the recessive allele (w)
Curly antennae are the dominant allele (C) and straight antennae are the recessive allele (c)
Bioluminescence is the dominant allele (B) and non-bioluminescence is the recessive allele (b)
Step 2: Determine the Parents’ Genotypes
Flip a coin (heads is dominant, tails is recessive) to determine the genotype of each parent for
each trait. Remember that there are two alleles for each trait, so two coin flips are required to
ascertain each trait genotype, e.g. if two heads are obtained for the mother’s EYE trait, her
genotype will be EE. If one head and one tail are obtained, her genotype would be Ee. If two
tails are obtained, the genotype would be ee. Record the results in the table, below.
Trait
Eyes
Wings
Antennae
Bioluminescence
Mother’s Genotype
Father’s Genotype
Step 3: Monohybrid Crosses and Predictions
Using the randomly determined genotypes, perform monohybrid crosses using Punnett Squares to
predict the possible genotypes of the offspring. Complete one Punnett Square for each trait.
Also, determine the genotypic and phenotypic ratios for each trait.
Eyes
Wings
Genotypic and Phenotypic Ratios:
Eyes


G-Ratio: __________________________
P-Ratio: __________________________
Wings
 G-Ratio: __________________________
 P-Ratio: __________________________
Antennae
 G-Ratio: __________________________
 P-Ratio: __________________________
Bioluminescence
 G-Ratio: __________________________
 P-Ratio: __________________________
Antenna
Bioluminescence
Step 4: Dihybrid Crosses and Predictions
Using the parents’ genotypes, choose two traits and using the Punnett Squares predicts the
possible genotypes of the offspring for those two traits. For example, if the mother’s genotype for
eyes is “Ee” and for wings is “WW”, and the father’s genotypes for those traits is “ee” and “Ww”,
the dihybrid cross will be “EeWW” x “eeWw”. After completing the Punnett Square, predict the
phenotypic ratio of each cross.
Phenotypic Ratio:
Genotypic Ratio:
Step 5: Determination of Offspring’s Genotype
Refer to the parental genotypes from Step 2. If the parental genotype for a specific trait is
homozygous recessive or dominant, the offspring will receive one of the respective alleles.
However, if the parental genotype is heterozygous, you will need to flip a coin to determine which
allele the offspring should receive. Remember, heads is the dominant allele and tails is the
recessive allele. Complete the table below:
Trait
Eyes
Wings
Antennae
Bioluminescence
Mother’s Genotype
Father’s Genotype
Offspring’s Genotype
Step 6: Creating the Alien Family
Now that you have the parental and offspring genotypes it is time to “translate” them into drawings
so we can see the phenotypes. Using 8 ½ x 11 unlined paper, draw the mother, father and offspring
of “your family” based upon the genotypes in your chart, above. Use colored pencils to add some
“pizzaz” to the drawings.