If you have two genes that are unlinked, they are independently inherited, such would be the case if the genes were on separate chromosomes or perhaps very far apart on the same chromosome. In these cases, inheritance of a particular allele of one gene is completely independent of the inheritance of the allele of a different gene. For example imagine the gametes produced from an individual heterozygous for two genes A and B. We'd expect the gametes:
(Original post by arvin_infinity)
Soo I thought this is codminance am I wrong!?
let me make my question a bit more clear then!
because the genes are "not linked" the gametes we get are
CwAf * CWAF- CWAS- CBAF-CBAS
now I wondered what would be the gametes if genes were linked!
AB Ab aB ab
since the alleles are not linked, we'd expect all these combinations to be equally likely. 25% would be AB, 25% ab, you get the picture.
If genes are linked it means that the two gene's alleles are actually fairly close on the same DNA molecule. If we look at a heterozygous individual for two linked genes, because they are on the same chromosome one of the alleles will stick around with the other, and are inherited together. Say our heterzygote has A&b on one chromosome, and a&B on the other. We won't get A&B, or a&b in our gamete because only one chromosome is added to each gamete. Except, often times we do, since during meiosis, the two different chromosomes align themselves together and crossover between the two different chromosomes take place - the process is fairly random, so close genes are unlikely to cross over, and further apart genes will cross over more frequently. So the frequencies of gametes produced will not be even for linked genes.
Co-dominance is simply when the heterozygous expresses both different alleles of one gene, clearly.
Last edited by Piprod01; 15-04-2012 at 19:17.