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Color Genetics of the Corn Ear Moth Larvae By Leah Friend, Madeline Reyes,

and Ben Troen

+Problem Statement:Does the color of the corn earn moth larvae display a simple mendelian inheritance pattern?Hypothesis:

If the color of corn ear moth larvae displays a simple mendelian inheritance pattern, then the dominant color allele would be tan.

+Background Info:Many visible traits in animals display a

simple mendelian inheritance pattern. This means the trait is controlled by one gene with a dominant and recessive allele.

The genotype of a simple mendelian trait can be described as homozygous dominant (AA), heterozygous (Aa), and homozygous recessive (aa).

The genotype of the organisms reflects the organism’s phenotype, or its observable trait. If the genotype contains the dominant allele the dominant trait is always reflected on the phenotype.

+Background Info:If two moths that are homozygous

dominant for a color (AA) were to be crossed all the offspring would display that dominant color and the phenotypic ratio would be 1:0

If two moths that are heterozygous for a color (Aa) were to be crossed the phenotypic ratio would be 3:1. 3(display dominant color):1(display recessive color).

If two moths that are homozygous recessive for a color (aa) were to be crossed all the offspring would display the recessive phenotype. The ratio would be 0:1

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+Materials:30 Original Corn Ear Moth LarvaeCupsSugar-water solutionMoth compartmentProcedures:1. To find the hypothesis for which color is dominant and which is recessive the color of all the worms were tallied. The color that is present at a higher frequency can be predicted to be the dominant color.

+Procedures: (continued)2. A moth habitat was built out of wood, tape, and screen.

3. Six larvae (3 tan, 3 red) were left alone with food until they pupated and then were transferred to the moth habitat.

4. Partitions were made in the moth habitat so that one tan male and one tan female were grouped together, one tan male and one red female were together, and one red male and one red female were grouped together.

+Procedures: (continued)5. In each partition the moths were allowed to reproduce.

6. Once the offspring hatched their colors were tallied and find the color to color ratio

7. If the color to color ratio of any of the crosses resembled some of the expected phenotypic ratios in a simple mendelian trait cross then it can be concluded the color is trait controlled by such as mechanism.

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+ Data:Data for Hypothesis:

Data for Tan x Tan cross: Individuals Percentage

Tan Color: 39 78%Red Color: 11 22%Total: 50 100%

Individuals PercentageTan Color: 21 70%Red Color: 9 30%Total: 30 100%

+ Data: (continued)Data for Tan x Red cross:

Data for Red x Red cross: Individuals Percentage

Tan Color: 14 60.8%Red Color: 9 39.2%Total: 23 100%

Individuals PercentageTan Color: 33 89%Red Color: 3 8.3%Green Color: 1 2.7%Total: 37 100%

+ Results:Phenotypic Ratios of Crosses

Cross Approximation of Ratio of Tan to Red to Green

Tan x Tan 5:1

Tan x Red 33:3:1

Red x Red 7:4

+Conclusion: In conclusion corn ear moth larvae color does not display a simple mendelian inheritance pattern. This is because none of the predictable ratios of simple mendelian crosses showed up in the data. Also the appearance of a newly observed green color sidesteps from a one gene, two allele model.

+Conclusion: (continued)Even though larvae color doesn’t display mendelian inheritance it could still be a result of genetics. Color could be a polygenic, multi-allelic, or an epigenically controlled trait.

+ The Three AmigosLeah Friend, Ben Troen, Madeline Reyes