WAEC SSCE - Agricultural Science - 2011 (Objective)

Question 1 Report

If T represents the gene for tallness while t represents dwarfness. The genotypic ratio of the second filial generation will be

3:1

1:2:1

2:2

4:0

Answer Details

When a tall (TT) crop is crossed with a dwarf (tt) crop, the resulting first filial generation (F1) will all be Tt (tall). This is because tallness is dominant over dwarfness. When these F1 individuals are crossed with each other, the genotypic ratio of the second filial generation (F2) will be 1 TT : 2 Tt : 1 tt. This is because each parent in the F1 generation can contribute either a T or t allele, resulting in four possible genotypes for the offspring: TT, Tt, Tt, and tt. Therefore, the genotypic ratio of the F2 generation is 1:2:1 (TT:Tt:tt). So, the answer is 1:2:1.






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