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

Explain genetically modified organisms, Q. Explain Genetically Modified Org...

Q. Explain Genetically Modified Organisms? Techniques that use gene modification through (a) recombinant DNA technology and (b) cellular techniques of introducing DNA into an o

What organisms make glycogen, What organisms make starch? What is it used f...

What organisms make starch? What is it used for? What organisms make glycogen? What is it used for?

Partial pericardiectomy-pericardial effusion, Partial Pericardiectomy :  ...

Partial Pericardiectomy :  The approach can be either by a left anterolateral thoracotomy or median sternotomy. For pyogenic pericarditis with adhesions and loculations a par

Glucose-6-phosphate to glucose, Glucose-6-phosphate to Glucose Glucose...

Glucose-6-phosphate to Glucose Glucose-6-phosphate to Glucose : Glucose-6-phosphate  is converted to glucose  by glucose-6-phosphatase which is present in intestine, liver and

What is the life cycle of a tapeworm, Q. What is the life cycle of a tapewo...

Q. What is the life cycle of a tapeworm? The Pregnant proglottids with taenia eggs are released together with human feces. If ingested by the intermediate hosts, bovineor swine

Density independent factors, Density Independent Factors Density inde...

Density Independent Factors Density independent factors are the extrinsic factors which tend to regulate the density of a population in ways that are not correlated with its

Define effect on human placental lactogen in pregnancy, Define effect on Hu...

Define effect on Human placental lactogen in pregnancy? Human placental lactogen, with a structure similar to the growth hormone, increases throughout pregnancy. Its rate of pr

Tetrasporic embryo sacs, Tetrasporic Embryo Sacs In this group neithe...

Tetrasporic Embryo Sacs In this group neither of the meiotic divisions is accompanied by wall formation so that at the end of meiosis all the four haploid nuclei remain in a

Structures of a flowering plant, Which structures of a flowering plant give...

Which structures of a flowering plant give rise to (a) potatoes, (b) the fleshy scales of an onion?   (a) A potato is a tuber formed at the end of an underground stem (b) O

Cell determination, Cell Determination Cell determination is a process...

Cell Determination Cell determination is a process through which portions of embryonic genome are selected for expression in particular embryonic cells. Determination to follo

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