Q1. A group of researchers studied variation in the number of abdominal bristles in female Drosophila. Two inbred strains that differed in bristle number were crossed to produce F1 hybrids. The variance in bristle number among the F1 flies as 3.33. These F1 flies were intercrossed with one another to produce an F2 population, in which the variance in bristle number was 5.44.

Q2. Two pure-breeding lines of Jersey cattle have mean weekly milk yields of 60 and 210kg. The F1 generation, which resulted from cross between the two lines, has a mean of 135kg and a variance of 16kg. What is the broad sense heritability (H2) for milk yield in this population?