BI111 Lecture Notes - Abscission, Auxin, Plant Hormone
Document Summary
Hormone: a signaling molecule secreted by a cell that can alter the activity of any cell with receptor for it. Dormancy: a period in the lifecycle in which biological activity is suspended. Circadian rhythm: any biological activity that is repeated in cycles, each about 24 hours long, independently of any shifts in environmental changes. Thigmotropism: growth in response to contact with a solid object. Nadistic movement: in plants, a reversible response to non-directional stimuli, such as mechanical pressure or humidity. Gravitropism: a directional growth response to earth"s gravitational pull that is induced by mechanical or hormonal influences. Statolith: a moveable starch- or carbonate-containing stone-like body involved in sensing gravitational pull. Second-messenger system: in particular , signal transduction pathway, an internal, nonprotein signal molecule that directly or indirectly activates protein kinases, which elicit cellular response. Abscission: in plants, the dropping of flowers, fruits, and leaves in response to environmental signals.
