Johnson State College, Biol1210: Intro to Biology
Monster Genetics Lab
(adapted from https://www.nlm.nih.gov/exhibition/harrypottersworld/pdf/teachersmonstergeneticslab.pdf)
You have learned about many different patterns of inheritance. Some are simple dominant or recessive, as in Mendelian traits. Some are more complex, such as incomplete dominant or codominant traits. In this lab you will investigate how a combination of these genes works to create an organism.
Part 1 Procedure:
In the table below, for each trait two potential alleles are described. Most use simple dominant/recessive type inheritance but some are specified as being controlled by incomplete dominance or codominance. Remember, incomplete dominance leads to an intermediate phenotype in heterozygous individuals and co-dominance means both traits are expressed in a heterozygous individual.
- Flip a coin twice to determine the genotype for each trait and record it in the data table. Heads = allele 1, Tails = allele 2 (Example: if you flipped heads twice, your monster will have two copies of allele 1 for his genotype.)
- Determine the phenotype resulting from the allele pair for each trait. Remember to take into consideration incomplete and codominance!
- Repeat steps 1‐2 for each trait and complete the female monster’s Table 1.
Table 1: Genotypes & Phenotypes for Female Monster
| Trait | Allele 1 | Allele 2 | Genotype | Phenotype |
| Eye | Two small eyes (E) | One large eye (e) | ||
| Eye Color (incomplete) | Red (R) | White (R’) | ||
| Skin Color (codominant) | Green (G) | Blue (B) | ||
| Tail Shape | Curly (C) | Straight (c) | ||
| Tail Color | Purple (P) | Orange (p) | ||
| Tail | Have tail (T) | No tail (t) | ||
| Teeth | Sharp (S) | Round (s) | ||
| Feet (incomplete) | Four toes (F) | Two toes (F’) | ||
| Horn Color | Purple (W) | White (w) | ||
| Ear shape | Pointy (Y) | Round (y) | ||
| Ears | No ears (N) | Two ears (n) | ||
| Claws | Long (L) | Short (l) |
Part 2 Procedure:
The female monster that you created in part 1 and a male monster (see Table 2 below) plan to have baby monsters. They are interested in finding out for each trait the probability that their offspring will have that trait.
- Fill in the missing genetic information in the table for the male.
Table 2: Genotypes & Phenotypes for Male Monster
| Trait | Genotype | Phenotype |
| Eyes | ee | |
| Eye Color (incomplete) | White | |
| Skin Color (codominant) | Green | |
| Tail Shape | Straight | |
| Tail Color | Pp | |
| Tail | No tail | |
| Teeth | Round | |
| Feet (incomplete) | FF’ | |
| Horn Color | ww | |
| Ear shape | yy | |
| Ears | Have 2 ears | |
| Claws | Short |
- Using the information you have about the genotype for the female and male monster for each trait, create Punnett squares* to predict what traits would result from a cross between the two monsters for each trait, and answer the following questions (see example below questions):
- Eyes – What percent of offspring will have only one eye? _________
- Eye Color – What percent of offspring will have red eyes? _________
- Skin Color – What percent of offspring will have green skin? _________
- Tail – What percent of offspring will have a tail? _________
- Feet – What percent of offspring will have three toes? _________
- Horn Color – What percent of offspring will have purple horns? _________
- Ears – What percent of offspring will have ears? _________
- Claws – What percent of offspring will have long claws? _________
Example: Ear shape
Imagine your female monster was heterozygous for ear shape (Yy) and we know the male monster is homozygous recessive (yy). Your Punnett square would look like this:
