Non-Mendelian inheritance

Non-Mendelian inheritance is a type of genetic inheritance that does not follow the laws proposed by Gregor Mendel in 1865. Mendel's laws, including the law of segregation and the law of independent assortment, apply to genes on different chromosomes or far apart on the same chromosome. However, non-Mendelian inheritance patterns include any pattern of inheritance in which traits do not segregate in accordance with Mendel's laws.

Types of Non-Mendelian Inheritance

Codominance

In codominance, both alleles for a gene are fully expressed in the phenotype. An example of this is the AB blood type in humans, where both the A and B alleles are expressed.

Incomplete Dominance

In incomplete dominance, neither allele is dominant over the other. The phenotype is a blend of the two parental phenotypes. An example of this is the color of snapdragon flowers, where a red-flowered plant and a white-flowered plant will produce pink-flowered offspring.

Multiple Alleles

Multiple alleles refers to the existence of more than two alleles for a particular gene within a population. An example of this is the ABO blood group system in humans, which has three alleles: A, B, and O.

Polygenic Traits

Polygenic traits are controlled by two or more genes, with each gene having a small additive effect on the phenotype. Examples of polygenic traits include height, skin color, and eye color in humans.

Sex-Linked Traits

Sex-linked traits are traits that are controlled by genes located on the sex chromosomes. In humans, examples of sex-linked traits include color blindness and hemophilia, which are both located on the X chromosome.

See Also

• Genetics
• Mendelian inheritance
• Gene
• Allele
• Phenotype
• Genotype

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  Four o'clock plant
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  Carl Correns
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  Incomplete dominance in Antirrhinum majus
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  Pavlovian black-white chicken rooster
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  Non-Mendelian inheritance
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  Non-Mendelian inheritance
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  Maternal inheritance - mitochondrial DNA