Question

You observe the following plant phenotypes in the F2 generation: 2706 tall/inflated, 930 tall/constricted, 888 dwarf/inflated, and 300 dwarf/constricted. Reduce these findings to a ratio and determine if they are consistent with Mendelian laws.

Answer 1

Based on the given information:

• Number of tall/inflated phenotypes = 2706
• Number of tall/constricted phenotypes = 930
• Number of dwarf/inflated phenotypes= 888
• Number of dwarf/constricted phenotypes = 300

The ratio can be determined by dividing all number by the smallest number (300 in this case)

• 2706 / 300 = 9.02
• 930 / 300 = 3.1
• 888 / 300 = 2.96
• 300 / 300 = 1

Therefore, the phenotypic ratio obtained is: 9.02 : 3.1 : 2.96 :1 which is consistent with Mendelian laws and expected phenotypic ratio for a dihybrid cross 9:3:3:1