A farmer grows crops with an average height of 5 feet. He breeds his tallest plants, which are each 8 feet tall. They produce offspring that have an average height of 5.25 feet.So, the heritability in this case is qa .The trait for height is .qbQa: 1: 0.08/ 2: 0.1/ 3: 0.5/ 4:0.8/Qb: 1 completly influenced by environment2 completely influenced by genes3 slightly influenced by environment4 slightly influenced by genes.

Answer: Qa: The heritability for tallness in these crops is 0.08, while Qb: Genes slightly influence the trait for height.Step-by-step explanation:Qa: The average height of regular crops grown by the farmer was 5 feet. The amazingly tall breeds have a 3feet increment than the usual crops. This progeny of the farmer's choice breeds has a 0.25 feet increment in height than what is expected in other normal breeds. Therefore, the heritability of the tall trait by these progeny was 0.25/3, which is 0.08333.....Approximately 0.08.Qb: This low heritability index showed that the trait for tallness is slightly influenced by gene, because if otherwise, the index would have been a far way higher than this. However, we cannot conclude that it is the environment that determines the tall phenotype to be expected in the crops; this renders other options wrong.