Answer:
<em>Exceptions to Mendel's principles:
</em>
Does exceptions mean that Mendel was "wrong"? The answer is "NO". It means that we know more today about diseases, genes, and heredity than compared to what he expalined 150 years ago. Here I have summerized the exceptions with examples:
<em>Incomplete dominance</em>: When an organism is heterozygous for a trait and both genes are expressed but not completely.
<em>Example</em><em>:</em> SnapDragon Flowers
<em>Codominance</em>: When 2 different alleles are present and both alleles are expressed.
<em>Example</em>: Black Feathers + Whites feathers --> Black and white speckled feathers
<em>Multiple alleles</em>: Three or more alternative forms of a gene (alleles) that can occupy the same locus.
Example: Bloodtype
<em>Polygenic traits</em>: more than one gene controls a particular phenotype
Example: human height, Hair color, weight, and eye, hair and skin color.