A geneticist developed a new type of pest-resistant walnuts. These walnuts produce 75% of pest-resistant walnut trees and 25% of susceptible (not resistant) trees when two resistant trees are crossed. If a grower crossed 100 such pairs of trees for 100 offspring and did this many times over many years and plots, she should get:
A)approximately 70% of resistant trees over all plots and years.
B)exactly 70% of resistant trees over all plots and years.
C)exactly 70% of resistant trees in all plots and years.
D)None of the answer options is correct.

Question

Quizplus · Accepted Answer

Since the new type of walnuts produce 75% pest-resistant trees and 25% susceptible trees when two resistant trees are crossed, the grower should expect approximately 75% of offspring from each pair of trees to be pest-resistant. Therefore, over many years and plots, the grower should expect an average of 70% of offspring to be pest-resistant (since there is some variation due to chance). Therefore, choice A is the best answer.

A Geneticist Developed a New Type of Pest-Resistant Walnuts