Answer:
Incomplete dominance is the inheritance pattern where the dominant allele did not mask the recessive allele completely and form a mix of both alleles. Here the inheritance is the incomplete inheritance. The ratio of F2 generation is 1:2:1.
Given:
R1R1 = 42
R2R2 = 39
R1R2 = 86
Total R1 alleles = 2*42+86 = 170
Total R2 alleles = 2*39+86 = 164
Total alleles = 334
Frequency of allele R1 = 170/334 = 0.51
Frequency of allele R2 = 164 / 334 = 0.49
Expected number of each phenotype:
Total population = 167
Blue = R1R1 = 0.51 * 0.51 * 167 = 43.44
Green = R2R2 = 0.49 * 0.49 * 167 = 40.10
Cyan = 2*R1*R2 = 2*0.51*0.49*167 = 83.46
Phenotype Observed(O) Expected (E) O-E (O-E)2 (O-E)2/E
Blue 42 43.44 -1.44 2.0736 0.0477
cyan 86 83.46 2.54 6.4516 0.0773
green 39 40.1 -1.1 1.2100 0.0302
Total 167 167 0.1552
Chi-square value = 0.155
Degrees of freedom = no. of phenotypes – 1
Df = 3-1 = 2
Critical value = 5.99
Chi-square value of 0.155 is less than the critical value of 5.99. So we accept the null hypothesis.
