BIOLOGY 152 Lecture Notes - Lecture 3: Earwax, Probability Distribution, Phenotype
20 Feb 2017
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Trait: a characteristic, often used interchangeably with phenotype. Environmental variation- caused by changes in environment continuous and discrete/discontinuous variation: continuous example- ear lobes- attached, semi attached, not attached or seed color- the whole spectrum of colors from white to red, with shades in-between. Its continuous, its not either just white or red because there are the shades in the spectrum in-between. A discrete variation is wet and dry earwax for example. There is a single gene with two alleles. The environment has little effect on variation in this trait. Geographic variation in allele frequency exists, with we in africans and. Europeans and dry in most koreans and east asian populations. If there is a single gene with few alleles in the population, it is likely a discrete variation. If there are multiple genes, there is likely continuous variation. Phenotypic plasticity- when a phenotype is influenced by changes in the environment. There are two types of frequency of alleles:
