Seedlings of the parasitic plant Cuscuta pentagona (dodder) huntby directing growth preferentially toward nearby host plants. Toinvestigate the possibility that the parasite detects volatilechemicals produced by host plants, a researcher placed individualdodder seedlings into a vial of water at the center of a circularpaper disc. A chamber containing volatile extracts from tomato (ahost plant) was placed at one edge of the disc, whereas a controlchamber containing only solvent was placed at the opposite end. Theresearcher divided the disk in to 4, equal-area quadrats to recordwhich direction the seedlings grew. 30 dodder plants were tested,and 17 grew toward the volatiles, 2 grew away from the volatiles(toward the solvent), 7 grew toward the left quadrant, and 4 grewtoward the right quadrant.
1) Is this an experimental or observational study?
2) State null and alternative hypothesis
3) Which test is appropriate for this study? T-test, contingencytest or goodness of fit?
