Plant tropisms--their directional movement in response to stimuli--are a fundamental concept in plant science and excite students because they are the observable signs of life in plants. Unfortunately, the precollege teaching literature is full of tropism misconceptions. An inexpensive clock clinostat is invaluable for student gravitropism and…

Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)

Describes how lectures, laboratories, and role playing can be used to introduce students to the importance of water quality of water used for plant growth. (PR)

Discusses traditional school demonstrations and experiments in hydrotropism. Explains that these experiments seem to "prove" hydrotropism, but yet most botanists reject hydrotropism. Teachers continue to teach the concept because it is logical and the experiments are simple. (PR)