Two Pure Lines of Nicotianum (Tobacco)have Significantly Different Corolla Lengths

Essay

Two pure lines of Nicotianum (tobacco)have significantly different corolla lengths.In line 1,the average length is 30 mm,ranging from 25 mm to 35 mm with a variance of 10.In line 2,the average corolla length is 60 mm,ranging from 45 mm to 65 mm with a variance of 12.The F₁ has a corolla length of 45 mm,ranging from 40 to 50,and the variance is 9.Upon selfing,an F₂ is produced that has an average flower length of 45 mm,but ranges from 10 mm to 80 mm with a variance of 55.
a)Provide a general explanation of these results.
b)Calculate the broad-sense heritability (H²)for corolla length in this study.