Example Of Non Mendelian Inheritance

Mendelian inheritance patterns involve genes that directly influence the result of an organism's traits and obey Mendel's laws.
Nearly genes in eukaryotic species follow a Mendelian design of inheritance. However, there are many that do not.
Non-Mendelian inheritance is a general term that refers to any design of inheritance in which traits do not segregate in accord with Mendel's laws. These laws draw the inheritance of traits linked to unmarried genes on chromosomes in the nucleus.

ane. Co-dominance

Co-dominance is believed to be a violation of the Police force of Dominance.
When the alleles for a particular trait are co-dominant, they are both expressed as rather than a ascendant allele taking complete command over a recessive allele.
This ways that when an organism has 2 different alleles (i.e., is a heterozygote), it volition express both at the same fourth dimension.

Case.

Speckled flowers where the plant breeder has bred 2 different colors of flower together, resulting in a speckled hybrid that has patches of color from both parents.

2. Incomplete Authorisation

Sometimes in a heterozygote ascendant allele does non completely mask the phenotypic expression of the recessive allele and there occurs an intermediate phenotype in the heterozygote. This is called incomplete dominance.
With co-ascendant alleles, both traits are expressed at the same time. With incomplete dominance, the aforementioned thing occur but the traits are blended together rather than occurring in detached patches.
Information technology thus refers to the status in heterozygotes where the phenotype is intermediate between the two homozygotes.

Instance.

In some plants the cross of red and white produces pink-flowered progeny (4-o'clock plants (Mirabilis jalapa) or snapdragons (Antirrhinum majus).

3. Polygenic Inheritance

Some traits are controlled by many genes such equally the summit, IQ, pare color, eye color etc.
Polygenic inheritance occurs when one feature is controlled by two or more genes.
Often the genes are large in quantity but small in effect.

Case. Skin Colour in Man

Davenport (1913) in Jamaica found that two pairs of genes, A-a and B-b cause the difference in skin pigmentation between negro and caucasian people. These genes were found to touch the character in additive fashion.

Thus, a true negro has four d o m i northward a n t genes, AABB, and a white has four recessive genes aabb. The F1 offspring of mating of aabb with AABB, are all AaBb and have an intermediate skin colour termed mulatto. A mating of two such mulattoes produces a wide variety of pare colour in the offspring, ranging from skins as dark as the original negro parent to equally white every bit the original white parent.

4. Multiple Alleles

Mendel studied but two alleles of his pea genes, but real populations ofttimes have multiple alleles of a given gene.

a. An example is ABO blood type in humans.

There are three common alleles for the gene that controls this characteristic. The alleles I^A and I^B are dominant over i. A person who is homozygous recessive ii has type O blood. Homozygous dominant I^AI^A or heterozygous ascendant I^Ai accept type A blood, and homozygous ascendant I^BI^B or heterozygous dominant I^Bihave type B blood. I^AI^B people accept type AB claret, because the A and B alleles are co-dominant. Type A and blazon B parents tin have a blazon AB child. Type A and blazon B parents tin also accept a child with Type O blood, if they are both heterozygous (IBi, IAi).

Type A blood: I^AI^A, I^Ai

Type B blood: I^B I^B, I^Bi

Type AB blood: I^AI^B

Type O blood: ii

b. Another example is the gene for coat color in rabbits (the C gene) which comes in four common alleles: C, c^chc^h, and c.

5. Pleiotropy

Some genes affect many different characteristics, not just a single characteristic.

An example of this is Marfan syndrome, which results in several symptoms (unusually tall peak, thin fingers and toes, lens dislocation, and heart problems). These symptoms although not seem to exist directly related, tin can be traced back to the mutation of a single gene.

half-dozen. Factor Linkage

Each chromosome contains more than 1 gene.
If the genes are situated in the same chromosome and are fairly close to each other, they tend to be inherited together.
This type of coexistence of two or more genes in the aforementioned chromosome is known as linkage.

For instance, some combinations of wing shape and body colour are inherited together. Fruit flies that have brown bodies are more likely to have normal wings, while fruit flies that have black bodies are more likely to accept vestigial wings.

vii. Actress-nuclear Inheritance

Though, the genes of nuclear chromosomes take a significant and key part in the inheritance of virtually all traits from generations to generations, they altogether cannot be considered as the sole vehicles of inheritance.

Certain experimental evidences propose the occurrence of certain extranuclear genes or Deoxyribonucleic acid molecules in the cytoplasm of many prokaryotic and eukaryotic cells. For eg. Mitochondria and chloroplasts take their ain Deoxyribonucleic acid and reproduce on their own within each prison cell.
Mitochondrial Dna is passed downwards from a mother to her offspring because the mitochondria in sperm cells don't get in into the egg. Thus, the entire mitochondrial Dna in the offspring —whether male or female—originally comes from the female person parent but.

References

Verma, P. South., & Agrawal, V. G. (2006). Prison cell Biological science, Genetics, Molecular Biology, Development & Ecology (i ed.). S .Chand and company Ltd.
Gardner, E. J., Simmons, Thousand. J., & Snustad, D. P. (1991). Principles of genetics. New York: J. Wiley.
http://www.untamedscience.com/biology/genetics/not-mendelian-genetics/
https://www.khanacademy.org/science/high-school-biology/hs-classical-genetics/hs-non-mendelian-inheritance/a/hs-non-mendelian-inheritance-review
https://www.ck12.org/biology/not-mendelian-inheritance/lesson/Non-Mendelian-Inheritance-BIO/
http://www.tusculum.edu/kinesthesia/home/ivanlare/html/genetics/nonmendel-master.html