Herbert the rat is put in a cage that is chilly. He operates in the environment by moving around the cage and bar-pressing. He discovers that moving around and bar-pressing have no impact on the temperature of the cage or anything else. Soon, Herbert stops moving around the cage at all. Even after the experimenter changes the situation and allows the temperature to be controlled through bar-pressing, Herbert fails to learn that he now has this control. Herbert is experiencing

Identify the missing parts of the carbon cycle

Which of the organisms listed below performs nitrogen fixation? a. legumes b. plants c. bacteria d. fungi

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.