Question

A farmer is growing apples. His crops produce an average of 120 apples per tree. If he selects a pair of trees that produce an average of 150 apples per tree, and the narrow-sense heritability of apples per tree is 0.66, what can he expect for the number of apples in the offspring trees if those two trees are mated?

a. 130 apples
b. 116 apples
c. 120 apples
d. 150 apples
e. 140 apples

Answer 1

Given the heritability of 0.66 and a phenotypic difference of 30 apples between the parent trees and the population mean, we calculate the expected number of apples in offspring trees, resulting in approximately 140 apples per offspring tree. The answer is option E.

Step-by-step explanation:

The student asked about the expected number of apples per offspring tree, given that two parent trees averaging 150 apples are mated and the narrow-sense heritability of apples per tree is 0.66. The narrow-sense heritability gives us the proportion of variance due to additive genetic variance, which in practical terms, indicates the fraction of the phenotypic difference between the parent and the population meaning that we can expect the offspring to inherit.

Since the population mean is 120 apples and the selected parents average 150 apples, we have a phenotypic difference of 30 apples.

The expected number of apples per offspring tree is calculated by adding the population mean (120 apples) to the product of the heritability (0.66) and the phenotypic difference (30 apples), which gives us:

120 apples + (0.66 x 30 apples) = 120 apples + 19.8 apples ≈ 140 apples.