Glossary 3031 Flashcards
Abscission
Leaf fall from deciduous trees in autumn
Abiotic environment
The non-living environment; the non-living influences on an organism.
Acclimitisation
The ability of an organism to adjust its tolerance limits or optimum range to slow changes in the environment.
Adaptation
An inherited characteristic that enables an organism to survive and reproduce in its habitat. Adaptions may be structural, behavioural or physiological.
Allelopathy
The production of toxic chemicals in the roots and leaves of a plant that prohibit the growth of other plants.
Auxin
A plant hormone that affects growth and development.
Biotic environment
The living environment; the influences of living organisms on one another.
Circadian
An event repeating itself about every 24 hours.
Dirunal
Daily or circadian rhythm.
Dormancy
A resting phase in an organism when metabolic rate falls to a low level.
Ecological niche
A description of how the organism feeds, opportunities provided by the habitat and the adaptative features of the organism that allow it to take advantage of these opportunities.
Ecosystem
A community of living organisms (biotic environment) together with non-living factors (abiotic environment), and the nutrient cycles and energy flows that connect all.
Endogenous
A factor or stimulus that originates within an organism.
Exogenous
A factor or stimulus that originates outside an organism.
Habitat
The place where an organism lives.
Long-day plants
Plants which flower in response to a day length longer than a critical period.
Nastic response
A non-directional movement of part of a plant in response to an external environmental stimulus.
Periodicity
Regularly changing behaviour.
Photoperiod
The relative amount of light and darkness in a 24-hour period.
Photoperiodism
A changing pattern or response based on length of light available.
Phytochrome
A protein pigment in plants sensitive to red and infrared light.
Plant hormone
A chemical that is produced in one part of the plant and has effects in another part.
Short-day plants
Plants that flower in response to a day length shorter than a critical period.
Stimulus
A change in the environment that causes a response in an organism.
Symbiotic (mutualistic) association
An association between two organisms for their mutual benefit.
Tolerance
An organism’s ability to survive variation in its environmental conditions.
Tropism
A growth response made by plants to external stimuli in their abiotic environment.
Vernalisation
The exposure of a plant to a period of low temperature to promote later growth and flowering.
Turgor
The rigidity of the plant tissue due to inflation of the cells with water
Haptonastic
Movements that are triggered by the intensity of touch.
Effector
The region of the plant where the groeth response occurs
Auxin
A plant hormone that affects growth and development
Exogenous
A factor or stimulus that originates outside an organism.
Endogenous
A factor or stimulus that originates within an organism.
Vernalisation
The exposure of a plant to a period of low temperature to promote later growth and flowering.
