Phenotype: Difference between revisions
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A phenotype is an observable trait in [[Organism| | A phenotype is an observable trait in an [[Organism|organism]]. It is the manifestation or expression of the genetic constitution or [[Genotype|genotype]]. | ||
Phenotypes are also affected by environmental factors e.g. an individual having the necessary [[Alleles|allele]](s) for height does not necessarily mean that | Phenotypes are also affected by environmental factors e.g. an individual having the necessary [[Alleles|allele]](s) for height does not necessarily mean that they will be tall, as heoght is influenced by proper diet and exercise. This suggests that a genotype will not always result in the same phenotype i.e. there are several phenotypes for one genotype. | ||
Another side to the example given above is that an individual without the alleles for height can still be tall given the proper combination of environmental factors. This means that one phenotype is not coded for by one genotype. Other complex phenotypes e.g. weight, behaviour, susceptibilty to disease, etc. are also coded for by several [[Genotype|genotypes]] <ref>Hartl D.L, Jones E.W. (2009) Genetics Analysis of Genes and Genomes, Seventh Edition, Massachusetts: Jones and Bartlett Publishers, Inc.</ref>.<br> | Another side to the example given above is that an individual without the alleles for height can still be tall given the proper combination of environmental factors. This means that one phenotype is not coded for by one genotype. Other complex phenotypes e.g. weight, behaviour, susceptibilty to disease, etc. are also coded for by several [[Genotype|genotypes]]; they are said to be [[polygenic|polygenic]] <ref>Hartl D.L, Jones E.W. (2009) Genetics Analysis of Genes and Genomes, Seventh Edition, Massachusetts: Jones and Bartlett Publishers, Inc.</ref>.<br> | ||
= Reference = | = Reference = | ||
<references /><br> | <references /><br> | ||
Revision as of 21:08, 8 December 2011
A phenotype is an observable trait in an organism. It is the manifestation or expression of the genetic constitution or genotype.
Phenotypes are also affected by environmental factors e.g. an individual having the necessary allele(s) for height does not necessarily mean that they will be tall, as heoght is influenced by proper diet and exercise. This suggests that a genotype will not always result in the same phenotype i.e. there are several phenotypes for one genotype.
Another side to the example given above is that an individual without the alleles for height can still be tall given the proper combination of environmental factors. This means that one phenotype is not coded for by one genotype. Other complex phenotypes e.g. weight, behaviour, susceptibilty to disease, etc. are also coded for by several genotypes; they are said to be polygenic [1].
Reference
- ↑ Hartl D.L, Jones E.W. (2009) Genetics Analysis of Genes and Genomes, Seventh Edition, Massachusetts: Jones and Bartlett Publishers, Inc.