Choose the correct statement
I) Alleles are unable to blend with other.
II) Genes are units of inheritance and alleles are slightly different forms of the same genes.
III) Mendel laws could be able to provide physical proof for the existence of genes (factors).
IV) Genes occurs in pairs and one pair segregate independently of another pair.

In mice black coat color (allele $\text{'}\mathrm{B}\text{'}$) is dominant to brown coat color (allele$\text{'}\mathrm{b}\text{'}$). The offspring of a cross between a black mouse $\left(\mathrm{BB}\right)$ and a brown mouse$\left(\mathrm{bb}\right)$ were allowed to interbreed. What percentage of the progeny would have black coats ?

Study the following statements about the blood groups,
A) The genes for Rh antigen are located on somatic chromosome pair-1.
B) Multiple alleles occupy different loci of homologous chromosomes.
C) The expression of blood types in man is by 3 alleles of a single gene.
D) Blood cells of the foetus are destroyed by Ig G type of antibodies.

From the above, identify incorrect statements.

Assertion (A): Dominance is not an autonomous feature of gene
Reason (R): Two traits show up equally in the heterozygote's phenotype in codominance