Name ______Period ______Score ______/20
Alien Alleles
Objective: Predict the phenotype(outward appearance) of offspring based on the genotype(genetic code) of inherited alleles.
Background: An allele is a location on a gene that codes for a particular trait. Each person (or alien) receives one allele from the mother and one allele from the father. Dominant alleles are always expressed, meaning that the trait shows up in the outward appearance if one of the dominant alleles is present in the genotype. Recessive alleles are shy, and only show up in the outward appearance when there are two recessive alleles. In co-dominance or incomplete dominance, there is a blending of traits in the outward appearance.
Instructions: You will be creating an alien and drawing the phenotype (outward appearance) based on the genotype (genetics) that will be picked at random. Your alien has only one chromosome pair with 5 alleles on it. You will need to draw the outward appearance of the alien based on the genetic code.
Materials: Each person should have a copy of this lab sheet, colored pencils or markers, 1 coin
Procedure:
Step 1- Flip the coin twice to determine eye shape. Heads are E, tails are e. Draw the appropriate eyes
on your alien on the back of the paper. (2 pts)
EE = large, buggy eyesEe = large, buggy eyesee = eyes with glasses
Step 2 –Flip the coin twice to determine the number of antennae. Heads are A, tails are a. Draw the
antennae on your alien. (2 pts)
AA = 2 antennaeAa = 3 antennaeaa= 4 antennae
Step 3-Flip the coin twice to determine the type of ears. Heads are R, tails are r. Draw the ears on
your alien. (2 pts)
RR = Elephant-type earsRr= Rabbit-type earsrr= Cat-type ears
Step 4-Flip the coin twice to determine the mouth shape. Heads are M, tails are m. Draw the mouth
on your alien. (2 pts)
MM = open mouth, big teeth Mm= open mouth, big teethmm=vampire fangs
Step 5 – Flip the coin four times to determine the skin color. Heads are B tails are b. Color the skin of
your alien. (2 pts)
BBBB = red BBBb = green BBbb = blue Bbbb= orange bbbb = purple
Analysis questions
1- Does your alien look exactly like anyone else’s alien? Explain with a complete sentence. (2 pts)
2-This alien had only 5 alleles total. Humans have several thousand alleles. Do you think it is possible for two unrelated humans to look exactly like each other? Explain your reasoning with a complete sentence. (2 pts)
3- Define these words: (hint – read the background information)
Dominant allele
Recessive allele
Co-dominant allele
Genotype
Phenotype
4- Which of the alien’s alleles were co-dominant?