Definitions Flashcards
Define a stimulus
A stimulus (plural: stimuli) is anything that causes a reaction in an organism or in any of its parts
Define a response
A response is the activity of a cell or organism as a result of a stimulus.
Define a tropism
A tropism is a change in the growth of a plant in response to an external stimulus.
Define a positive tropism
A positive tropism occurs when the growth is towards the stimulus.
Define a negative tropism
A negative tropism occurs when the growth is away from the stimulus.
Define phototropism
Phototropism is the change in growth of a plant in response to light, usually from one direction (.e. unidirectional light)
Define geotropism
Geotropism (or gravitropism) is the change in growth of a plant in response to gravity.
Define thigmotropism
Thigmotropism is a change in growth of a plant in response to touch.
Define hydrotropism
Hydrotropism is a change in growth of a plant in response to water
Define chemotropism
Chemotropism is a change in growth of a plant in response to chemicals.
Define a growth regulator
A growth regulator is a chemical that controls the growth of a plant
Define a growth promoter
A growth promoter is a chemical that causes increased growth in plants
Define a growth inhibitor
A growth inhibitor is a chemical that causes a reduction in growth of plants
