What is Co - Dominance (Genetics) ? How some Cattles have two hair colours?

Co - dominance - In this both the allelic genes show their expressions. Two Hair colours in the cattles is due to the co - dominance.

  img. Source - Pixabay

                           

Co - Dominance Definition - 

If both of the allelic gene pairs show the equal and simultaneous expression with the same organism, the organism is called co - dominant and the process is called the co - dominance.

So the offspring shows the traits (characters) of both the parents unlike dominance in which only dominant character is shown.

Examples -

1. Hair colour in the cattles.
2. Blood Group 'AB'.
3. Blood Group 'MN'.
4. Sickle Cell Trait (Hb^A Hb^S).- in it one gene for the haemoglobin is normal and another is sickle cell. So some RBC are formed normal and some formed Sickle Celled, so both the genes are showing their equal expression that is showing Co - dominance.

Unlike Sickle Cell Anemia (Hb^S Hb^S) in which all the RBC are sickle shape so destroyed by the body so person become anematic.

Hair Colour in Cattles- 

parents →      Black haired Cattles           ❌              White haired Cattles

                               BB                                                          bb

                                                                      ↓

F1  →                               Roan Cattles (cattles with two colour)

                                                              Bb

                                                                         ↓

                                                                      

                                                                 Sibmating

                                                                         ↓

             

      F2  →

	B	b
B	BB	Bb
b	Bb	bb

           Black : Roan : White

                      BB    :  Bb    :    bb
                   
                        1      :   2      :    1


 I hope you liked the information about the co dominance and now you are able to understand .what Co - dominance is.