A geneticist is conducting research on pest-resistant walnut trees. He has developed a set of trees, when crossed, to produce offspring as follows: 40% of all trees are very resistant, 30% of trees are somewhat resistant, and 20% are susceptible to invasion by pest, for the rest susceptibility status is unknown. Which of the following is a valid probability for an experiment of crossing two trees from his set?
A)P(susceptible)= 0.4, P(somewhat resistant)= 0.3, P(susceptible)= 0.2
B)P(susceptible)= 0.5, P(somewhat resistant)= 0.3, P(susceptible)= 0.2
C)P(susceptible)= 0.4, P(somewhat resistant)= 0.3, P(susceptible)= 0.3
D)None of the answer options is correct.

Question

Quizplus · Accepted Answer

None of the answer options is correct as each option includes a repeated probability of susceptibility, which is not possible in the given set of trees. The probabilities must add up to 100%, and each category is mutually exclusive, meaning that a tree cannot be both somewhat resistant and susceptible at the same time. Therefore, a valid probability would be a combination of different categories, such as P(very resistant) and P(somewhat resistant), etc.

A Geneticist Is Conducting Research on Pest-Resistant Walnut Trees