Tropism
The reaction to a certain stimulus in the environment
Hydrotropism
When a plant grows toward water
Thigmotropism
When a plant grows toward touch
Phototropism
When a plant grows toward light
Gravitropism
When a plant grows reacting to gravity
Stimulus
When an organism reacts to the five senses
Negative Tropism
When organism moves away from a stimulus
Positive tropism
When an organism moves toward a stimulus
Thermotropism
When an organism reacts to temperature
Response
The action taken after the stimulus.
Nastic Response
A plant’s response to touch, but is not directional! Although it may appear to be similar to thigmotropism, it is neither directional nor permanent. Movement is a result of turgor pressure.
Auxins
Plant hormones that lead to phototropism by elongating the dark side of the plant
Gibberellins
Plant hormones that produce dramatic increases in size during a plants various life cycle stages.
Cytokinins
Plant hormones that stimulate cell division and cytokinesis
Oligosaccharins
Growth promotor Production site-cell walls Effects-stimulates antibiotic manufacture; complex carbohydrate molecular signals for the plant
Abscisic Acid
inhibits cell growth, helps close stomata
Ethylene
A gaseous plant hormone that promotes fruit ripening and opposes auxins in its actions
Studied by 46 People
