Question

Grain colour of wheat is determined by three pairs of polygenes. In cross AABBCC x aabbcc, progeny resembling either parent in $F_2$ generation is

• A. Half
• B. One third
• C. Less than 5%
• D. 75%

Answer 1

The correct option is C Less than 5%

Polygene results in quantitative inheritance. Quantitative inheritance is characterized by the occurrence of intermediate forms between the parental type. There will be 7 ( 1 : 6 : 15 : 20 : 15 : 6 : 1 ) phenotypes when three polygene pairs are involved. The total number of progeny would be 64. Out of these sixty-four only two will be likely to resemble either parent. Hence their proportion in F2 generation would be 3.12 i.e. less than five percent.

So, the correct option is 'Less than 5%'