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1. Range of dominance:
complete incomplete codominance.
Ex. Tay-Sachs 2. Nothing to do with abundance or fitness of alleles in
Ex. Polydactyly Multiple Alleles
= Existence of more than two alleles of the same gene.
- Most populations dozens hundreds alleles per locus.
* Note: One individual cannot carry > 2 alleles at a time.
Ex. Leaf patterns/coloration in White clover Ex. Human blood type determined 3 alleles:
IA, IB (codominant)
Generate 6 possible genotypes and 4 phenotypes: Pleitropy
= When a single gene affects more than one phenotypic trait. Ex. Frizzle gene in chickens
- feathers curl upward
- abnormal body temperature
- higher metabolic & blood flow rate
- greater digestive capacity
- lay fewer eggs
Ex. Phenylketonuria (PKU) in humans
- mental retardation
- reduced hair and skin pigmentation Gene x Environment Interactions
- Strong effect on phenotypes produced by most genes.
Ex. Effect of food deprivation on growth.
Ex. Fur color in Himalayan rabbits and Siamese...
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This note was uploaded on 02/24/2014 for the course BIOL 180 taught by Professor Freeman during the Winter '07 term at University of Washington.
- Winter '07