When both dominant and recessive alleles express their traits simultaneously,it is called.....

Formation of $AB$ type of blood group in humans is due to . . . . . . inheritance.

If two individuals with $AB$ blood group marry and have a large number of children,the children show $A$,$AB$,and $B$ blood groups in a ratio of $1:2:1$. Since proteins of both $A$ and $B$ types are present in individuals with $AB$ blood group,this is an example of:

Codominance is shown by the gene controlling:

In short-horned cattle,genes for red $(R)$ and white $(r)$ coat colour occur. $A$ cross between red $(RR)$ and white $(rr)$ produces $(Rr)$ roan. This is an example of:

Write a short note on co-dominance.