Question

11. A strawberry farmer determines that the average weight of individual strawberries produced by plants in his garden is 3 g. He selects the 10 plants that produce the largest strawberries; the average weight of strawberries among these selected plants is 6 g. He interbreeds these selected strawberry plants. The progeny of these selected plants produce strawberries that weigh 4 grams.

If the farmer were to select plants that produce an average strawberry weight of 7 g, what would be the predicted weight of strawberries produced by the progeny of these selected plants?

Answer 1

The correct answer is 2.99g

Explanation:

The workhorse equation for quantitative genetics is R = h² S. R is the response to selection, S is the selection differential, ie, the difference between the mean of the initiating population and the mean of the progeny of the selected parents. S is the selection differential and h² is the narrow-sense heritability.

In the given question R = 4g - 3g = 1g.

                                   R = 1g

In the given question S = 6g - 3g = 3g

                                  S = 3g

Substituting the values of R and S in the given equation, we get:

1g = h² (3g)

h² = 0.33

If the selected plants' average weight is 7 grams, then S would be 3 grams, and R = 0.33 × 3 = .99 g

The predicted average weight of strawberries from the progeny plants would be 2g + .99 g = 2.99 g.