Male amphibians, including frogs and toads, have been plagued by feminization, deformity, behavioral abnormalities and sterility. Biologists from the University of Florida investigated whether reproductive problems among populations of cane toads (Bufo marinus) are caused by poisons from chemicals associated with agriculture. The biologists collected local adult cane toads from more than 20 different locations. Toads were collected from areas close to agriculture, both large-scale and small-scale farms, as well as from suburbs that are nonagricultural areas. Based on this study, what is/are the test group(s)

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a. one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b. one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c. one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.