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Polygenic Lab

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Introduction Human Height Polygenic traits are not expressed as absolute or distinct characters as was the case with Mendel's pea plant traits. Instead, polygenic traits are recognizable by their expression as a continuous variation. Height in humans is a polygenic trait. If you line up the entire class a range of variation is apparent, with an average height at the high point in the middle. Traits showing continuous variation are usually controlled by the additive effects of two or more separate gene pairs. This is what gives polygenic traits so many alleles and, therefore, so many genotypes. Usually polygenic traits are distinguished by traits usually quantified by measurement rather than counting, two or more gene pairs contributing to the phenotype, or phenotypic expression of polygenic traits varying over a wide range. ...read more.


So... If human height is a polygenic trait and polygenic traits have phenotypic variation, then human height should have a phenotypic variation. Human Ear Lobes If ear lobes are determined by a one gene trait and one gene traits have two alleles, then ear lobes are decided by two alleles making it have two genotypes. Data (Human Height) Biology class (period 3) Height (cm)(tens place) Height (cm)(ones place) 180 1,1,3 170 1,3,3,4,8 160 0,3,4,5,6,6,6,6,7,9 150 5,5,6,6,8 Biology class (period 1-3) Height (cm)(tens place) Height (cm)(ones place) Period 1 Period 2 Period 3 180 0,1,1 0,6,6,7,8,8 1,1,3 170 0,0,0,1,2,2,3,4,5,5,5 0,2,3,4,6,6,7 1,3,3,4,8 160 0,2,3,3,4,5,7,8,9,9 1,2,2,5,5,6,6,8,8,8,8 0,3,4,5,6,6,6,6,7,9 150 4,7,9 7,7 5,5,6,6,8 10 people Height (cm)(tens place) ...read more.


where a simple height gene has mutated and is present in many copies (alleles) and all alleles contributing to the height. There are so many alleles controlling this one trait that when they all get mixed up lots of outcomes are available. Human Ear Lobes My hypothesis that stated, if ear lobes are determined by a one gene trait and one gene traits have two alleles, then ear lobes are decided by two alleles making it have two genotypes, was true. If ear lobes are only determined by one gene then there are going to be two alleles. There is not a very big variation in the ear lobes because it is one gene trait, so no matter how you arrange the two alleles one is going to be dominant and one is going to be recessive, making only two outcomes. ...read more.

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