Codominance, Biology

Assignment Help:

CODOMINANCE

The alleles which do not show dominance-recessive relationship and are able to express themselves independently when present together are called codominant alleles. Independent expression of two alleles in an individual is termed codominance.

Example :- 1

Coat colour in short horned cattle

There are two types of pure short horned cattle, red and white. On cross breeding the individuals of F1 generation are found to have roan colour. The effect is produced due to juxtaposition of small patches of red and white colour. It is also known as mosaic inheritance. As both the alleles form small patches side by side, they are codominant. It was previously considered to be a case of incomplete dominance because the colour effect is intermediate between red and white, on in breeding the roan hybrids produce three type of cattle-red, roan and white in the ratio of 1 : 2 : 1.

Example :- 2

AB Blood Group

Alleles for blood group A (IA) and blood group B (IB) are codominant so that when they come together in an individual they produce blood group AB. It is characterised by the presence of both antigen A (from IA) and antigen B (from IB) over the surface of erythrocytes.

Example :- 3

MN Blood Group

This phenomenon has been observed in MN blood group in humans. The red blood cells can carry two types of native antigens M and N, and an individual can be MM, MN or NN, exhibiting either one or both of them.

Example :- 4

Sickle Cell Haemoglobin

The allele for sickle cell haemoglobin Hbs is codominant with allele for normal haemoglobin HbA.


Related Discussions:- Codominance

What are the five human digestive secretions, What are the five human diges...

What are the five human digestive secretions? Which of them is the only one that does not contain digestive enzymes? The human digestive secretions such as: saliva, gastric jui

Why the vast majority of segregation errors in human patient, Which of the ...

Which of the following defines why the vast majority of segregation errors in human patients include the two sex chromosomes (XXY, XO, XYY) or chromosome 21 (triple 21)? A. Th

Sterigmatocystin, These mycotoxins are structurally and biologically relat...

These mycotoxins are structurally and biologically related to the aflatoxins, and like the latter, they cause hepatocarcinogenic activity in animals. Among the organisms that prod

Usefulness of bacteria in a natural environment, Give one example in each c...

Give one example in each case of the usefulness of bacteria in (a) a natural environment, (b) an industrial process.   (a) In a natural environment bacteria brin

Composite endosperm - variants of endosperm, Composite Endosperm - Variants...

Composite Endosperm - Variants of Endosperm In the family Loranthaceae, the development of endosperm is unique. The ovary lacks ovules. The sporogenous tissue located at the b

Ecosystem as a unit of nature , Ecosystem as a Unit of Nature An ...

Ecosystem as a Unit of Nature An ecosystem can be visualised as a functional unit of nature representing complex interactions between living and non-living components. Th

Explain diet history and nutrient intake, Explain Diet history and nutrient...

Explain Diet history and nutrient intake Diet history  and  nutrient intake : This  is used  to evaluate diet for nutrient or food intake. Common methods used include the 24-h

What do you mean by descending aorta, Q. What do you mean by Descending Aor...

Q. What do you mean by Descending Aorta?  The descending aorta begins at the level of the fourth thoracic vertebra. It is defined through the cardiac shadow on the CXR, as it l

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd