can anyone give a clean definition?> (1 Viewer)

[psycho_mushy]

can any of u l33t's out ther give a clear definition of:

1) multiple alleles and

2) polygenic inheritance

I got some already, but they don't seem to make the task anymore easier...

these are mine correct me if I'm wrong:
multiple alleles: two or more phenotype traits present in the organism controlled by genes but only two can be expressed at any one time..... corrections?

polygenic inheritance: multiple genes control multiple alleles that are to be presented as phenotypes. More than one factor is involved for the allele to be presented i.e. height

thanks heaps

 

[Bannanafish]

the phenotype is determined by multiple genes (because of the on gene one polypeptide theory)

 

[tempco]

Multiple alleles: When a single characteristic is determined by multiple alleles (3 or more), but only 2 can be present in the genotype of the organism.

Polygenic Inheritance: When a single characteristic is determined by multiple pairs of alleles on different loci (positions on a chromosome).

 

[psycho_mushy]

I still don't kinda get polygenic.... can u give an example? sorry

 

[tempco]

Ok. Well, skin colour is determined by polygenic inheritance, by 3 pairs of alleles. For the first pair of alleles, the two genes are a' (dark) and a (light). For the second, the genes are b' and b. For the third, c' and c. These pairs of genes are on different loci; they maybe on different chromosomes or on the same one, but they do not share the same position on a chromosome. I really dark skinned person would have the genotype a'a' b'b' c'c' while a really light person would have the genotype aa bb cc.

Hope that clears it up for you.