+ Color Genetics of the Corn Ear Moth Larvae By Leah Friend,
Madeline Reyes, and Ben Troen
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+ 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.
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+ 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 organisms phenotype, or
its observable trait. If the genotype contains the dominant allele
the dominant trait is always reflected on the phenotype.
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+ 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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+
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+ Materials: 30 Original Corn Ear Moth Larvae Cups Sugar-water
solution Moth compartment Procedures: 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.
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+ 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.
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+ 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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+
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+ Data: Data for Hypothesis: Data for Tan x Tan cross:
IndividualsPercentage Tan Color:3978% Red Color:1122% Total:50100%
IndividualsPercentage Tan Color:2170% Red Color:930%
Total:30100%
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+ Data: (continued) Data for Tan x Red cross: Data for Red x
Red cross: IndividualsPercentage Tan Color:1460.8% Red Color:939.2%
Total:23100% IndividualsPercentage Tan Color:3389% Red Color:38.3%
Green Color:12.7% Total:37100%
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+ Results: Phenotypic Ratios of Crosses CrossApproximation of
Ratio of Tan to Red to Green Tan x Tan5:1 Tan x Red33:3:1 Red x
Red7:4
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+ 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.
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+ Conclusion: (continued) Even though larvae color doesnt
display mendelian inheritance it could still be a result of
genetics. Color could be a polygenic, multi-allelic, or an
epigenically controlled trait.
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+ The Three Amigos Leah Friend, Ben Troen, Madeline Reyes