Dr. Young is a coastal plant ecologist studying symbiotic root nodule-forming bacteria that must be present in soils on the Eastern Shore of Virginia in order for woody plants to grow. Dr. Young is studying how these bacteria are dispersed over a coastal barrier island and hypothesizes that bird droppings may transport the bacteria to young soils either locally or long-distance. To test this hypothesis, you germinate two hundred sterile shrub seedlings, each of which you then assign to one of the following treatments to test for nodule development (successful bacterial infection):
Treatments were as follows:
PR: Positive Reference; crushed nodules
NR: Negative Reference; distilled water
BI: Barrier Island field-collected bird dropping suspension
ML: Mainland-collected bird dropping suspension
For this experiment, the null and alternative hypothesis are:
A: Nodulation is independent of seedling treatment
B: Nodulation is related to (not independent of) seedling treatment
C: Nodulation is correlated to bird dropping exposure.
D: There is no difference between exposure to mainland or island bird droppings