Crossing of pure black, rough haired with double recessive white, smooth haired Guinea pigs.
Character - I – Colour Black ---White
Character - II - Nature of the hair Rough ---Smooth
A. Crossing of ‘p’generation:
When pure double dominant black,rough haired Guinea pig is crossed with double recessive white, smooth haired pig, all F1 individuals are dihybrid black and rough haired. It indicates
that black and rough are dominant over white and smooth hair respectively.
B. Crossing of F1 dihybrid individuals:
When dihybrid black and rough haired Guinea pigs are crossed, in F2 , 4 types of phenotypes are produced. They are
i. Double dominant - Black rough -9/16
ii. Recombinant - I Black smooth - 3/16
iii. Recombinant -Il White rough -3/16
iv. Double recessive - white smooth -1/16
In F2, the formation of recombinants indicates that every contrasting form behaves independently. Hence mE2, in addition to parent combinants (Black rough, white smooth), two new combinants (Black smooth, white rough) are also produced.
