Two Highly Inbred Populations of the Annual Weed Capsella Bursa-Pastoris

Essay

Two highly inbred populations of the annual weed Capsella bursa-pastoris grow in adjacent fields.One field is mowed regularly;the other is never mowed.Seeds from the plants are taken to a greenhouse where they can be grown under uniform conditions.The mean height of plants at the time of flowering is measured for each population,and for the F₁ and F₂ generations from crosses between representatives of each population.The data from these experiments are as follows:
$\begin{array}{|l|r|r|}\hline& \text { Mean } & \text { Variance } \\&\text { (in cm) } &\\\hline \text { Mowed Field } & 6.2 & 4.0 \\\hline \text { Unmowed Field } & 13.6 & 10.2 \\\hline F_{1} & 10.2 & 12.6 \\\hline F_{2} & 10.4 & 20.3 \\\hline\end{array}$

a)How much of the observed variance in plant height at flowering is caused by the environment in which the plants are grown?
b)How much of the variance is due to genotype?
c)What is the broad-sense heritability (H²)for this character?