Mendelian Inheritance
Description: In this lab you will practice using Punnett Squares in a chicken breeding experiment.
SIMPLE TRAITS
Please read the following statement and answer the question fully.
· According to the Mendelian principle of dominance and recessiveness, a dominant allele is always expressed over a recessive allele in a genotype controlling for discrete phenotypes. As such, do you think that dominant traits are always more common than recessive traits in a population? Why or why not? (4 points)
PUNNETT SQUARES
As we learned this week, there are mathematical ways of determining how traits are passed between generations. In this section of the lab, you will work with Punnett Squares to breed speckled chickens. Currently, you have two roosters, one brown and one white to breed with your speckled hen. You know from reading a genetics paper that the speckled allele is “a,” meaning that you need a homozygous recessive genotype of “aa” to produce a speckled offspring. You also know that the brown rooster you will be breeding is heterozygous for the “brown phenotype” and the white rooster you will be breeding is homozygous dominant for the “white phenotype.” Using Punnett Squares, please simulate the breeding of your brown rooster with your speckled hen and then your white rooster with your speckled hen. Afterwards, answer the questions on the following page. (10 points)
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· Which rooster is more likely to contribute to the production of speckled offspring? How do you know? (3 points)
· What are the odds for each breeding experiment that speckled offspring will be produced? (Please write your answers as %) (3 points)
