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 crosses two such trees, the outcome is random and a probability model is given by outcomes:
A)resistant with probability 0.5 and susceptible with probability 0.5.
B)resistant with probability 0.75 and susceptible with probability 0.75.
C)resistant with probability 0.25 and susceptible with probability 0.25.
D)resistant with probability 0.75 and susceptible with probability 0.25.

Question

Quizplus · Accepted Answer

The question states that when two pest-resistant walnut trees are crossed, 75% of the offspring are also pest-resistant while 25% are susceptible. This means that the dominant trait of pest-resistance is expressed 3 out of 4 times, which corresponds to a probability of 0.75. Therefore, choice D is the best option as it reflects this probability model.

A Geneticist Developed a New Type of Pest-Resistant Walnuts