Explains the mechanisms and describes the processes that underlie gravitropism in roots. Reviews experimental efforts and investigative results that explored the causes of root behavior. (ML)

Discusses the biochemical mechanisms related to photosynthesis. Describes a water-oxidizing clock generating a molecule of oxygen with every four ticks. Lists four references. (YP)

A database had been developed for the Phoenix Desert Botanical Garden's Living Plant Collection using Statistical Analysis System software. Implementation procedures, data dictionary maintenance, data entry, updating, and reporting are described. (JN)

Updates knowledge on nitrogen fixation, indicating that investigation of free-living nitrogen-fixing organisms is proving useful in understanding bacterial partners and is expected to lead to development of more effective symbioses. Specific areas considered include biochemistry/genetics, synthesis control, proteins and enzymes, symbiotic systems,…

The use of green, red, and far-red light-emitting diodes (LEDs) as light sources for plant physiological studies is outlined and evaluated. Indicates that LED lamps have the advantage over conventional light sources in that they are lightweight, low-cost, portable, easily constructed, and do not require color filters. (Author/DH)

Describes the experimental procedure and expected outcome in the growth of rice seedlings with light conditions and water aeration as variables. (GS)

This workbook provides descriptions of research projects for high school and middle school science teachers and students. The projects can be used as demonstrations in the laboratory or classroom to help teachers illustrate the practical application of basic science principles. They can also be used by students, under the guidance of the teachers,…

Examines the role played by botany and chemistry in the development, exploitation, and later deterioration of tropical economies. Although near equals in 19th-century international trade, the development of synthetics by European scientists in the early 20th century crippled the tropical economies. Research, innovation, and investment protected…