Explain Multiple Alleles and the concept of Dominance with an example.

(N/A) $1$. Multiple Alleles: In this case,more than two,i.e.,three or more alleles are present governing the same character. Multiple alleles can be found only when population studies are conducted.
$2$. Dominance: Dominance is not an autonomous feature of a gene or the product that it has information for. It depends on the gene product and the production of a particular phenotype from this product,as well as the particular phenotype that we choose to examine.
$3$. Example (Starch synthesis in pea seeds): Starch synthesis in pea seeds is controlled by one gene with two alleles ($B$ and $b$).
- $BB$ homozygotes synthesize starch effectively,producing large starch grains (Round seeds).
- $bb$ homozygotes have lower efficiency,producing smaller starch grains (Wrinkled seeds).
- Heterozygotes $(Bb)$ produce round seeds,suggesting $B$ is dominant for seed shape.
- However,the starch grains in $Bb$ seeds are of intermediate size. Thus,if starch grain size is the phenotype,the alleles show incomplete dominance.
- This demonstrates that dominance depends on the phenotype chosen for examination.