Download Cooties Terminology

Genes are pieces of information in the form of DNA that tell the cells of an organism what to do in order to
function. For example, your muscle cells need to make muscle proteins, which allow you to move; the
information to make muscle proteins is stored in your genes. Some parts of you are easy to see such as your
hair and eyes. But some parts are not so easy to see, such as the enzymes that digest your food. Your genes
determine all of these components, which make up who you are. In cootie genetics we called the
components that made up the cootie traits or characteristics.
You have two copies of all of your genes, one that you received from your mom and one that you received
from your dad. For most of your traits the gene you got from your mom is the same as the gene from your
dad. However some variation of genes is seen. A classic example of this is eye color. The variation can be
due to two or more versions of a gene for a trait. Two different versions of a gene are called alleles. For
example: blue/brown eye color exists because of two alleles of a gene. Generally, if you have two blue
alleles of the eye color gene (remember you receive one allele from mom and the other from dad) then you
have blue eyes. If you have two brown alleles then you have brown eyes. But what happens if you received
a blue and a brown allele? Perhaps the color blends and you get kind of a grayish, purplish eye color? It
turns out, though, that generally traits do not blend and what you usually see if you have one blue and one
brown allele is brown eye color. So what happened to the blue? The blue is still there but not seen. For
most genes one of the alleles overrides information of the other allele. The allele that you see (brown in this
case) is called dominant, whereas the allele that you do not see (blue) is called recessive. Which alleles were
dominant for the five different cootie traits observed in the cootie genetics activity?
If an individual has the same allele for a specific gene version they would be homozygous for that gene; two
different alleles would be heterozygous. Because blue eye color is recessive, in order to have blue eyes you
would expect to be homozygous for this gene, both of your eye color genes would be blue. However, if you
were heterozygous (Brown/blue) or homozygous (Brown/Brown) then you should have brown eyes.
The 5 visible cootie traits are:
Body/Head color
Auditory Appendages (Ears)
Ocular Appendages (Eyes)
Vocal Appendages (Mouth)
Motility Appendages (Legs)
In the population of Cooties that you reproduced, each of the above traits had two (2) possible versions
(alleles) that can result in differences in the visible trait.
Body color-Red or blue (Red is dominant to blue)
Auditory Appendages-Wide-ear or bow (Wide-ear is dominant to bow)
Ocular Appendages-Purple or lashes (Plain Eyes are dominant to lashes on eyes)
Vocal Appendages-Lips or tongue (Lips are dominant to tongue)
Motility Appendages-Boots or bare-feet (Boots are dominant to bare-feet)
During the mating of the cooties you were able to make cooties with different combinations of alleles than
what you started with in Mom and Dad or even Grandma and Grandpa. Remember Mom and Dad were both
heterozygous for all five traits. The genotype was RrWwPpLlGg (mom) and RrWbPlLtGb (dad), while the
phenotype was Red body, wide ear, plain eyes, lips and boots. Genotype refers to the allele combination,
whereas phenotype is the trait that we can see. Also remember Grandma’s genotype was RRWWPPLLGG
and Grandpa’s rrwwppllgg. Can you see why the babies from the mating between the cootie from the east
(Grandma) and the cootie from the west (Grandpa) resulted in only heterozygous babies that all looked like
Grandma?