animal and plant responses Flashcards
What are tropisms?
A directional growth response to a directional stimulus only in plants
What is a nastic response?
Non directional response to plants to the intensity of the stimulus
What is taxis?
Movement of an animal towards (positive) or away from (negative) a directional stimulus
What is kinesis?
A random movement response in animals where the rate of activity is determined by the intensity of the stimulus (non-directional)
What are migration cues?
Changes in daylength, food, availability, temperature
What is nyctnasty?
Circadian rhythmic nastic movement of plants in response to the onset of darkness
What is innate behaviour?
Any genetically determined behaviour, not learned
What is orthokinesis?
The speed of movement is related to the intensity of the stimulus
What is klinokinesis?
The amount of random turning is related to the intensity of the stimulus
What is cell elongation?
Method by which plant grows towards or away from a stimulus
What is IAA?
Hormone responsible for many tropisms
What is homing?
A frequent activity where animals return to a nest or buttow after going out to find food or mates
What is a compass?
Way animals navigate when migrating
What is a solar compass?
Navigation using the position of the sun in the sky
What is a magnetic compass?
Navigating using the earth’s magnetic compass
What is a stellar compass?
Navigating using the position of stars in the night sky
What is migration?
The mass movement of populations between habitats
What is tropotaxis?
The animal compares intensity of a stimulus using two or more sense organs on either side of it’s body to determine the direction of the stimulus
What is klinotaxis?
Where the animal determines the direction of the stimulus by moving a single sense organ and comparing relative intensities.
What is a zeitgeber?
Environmental cue that resets the internal biological clock
What is a free running period?
Cyclic behaviour seen in the absence of external cues
What is entrainment?
Resetting of internal biological clock by environmental cues
What is phase shift?
How much the period of activity is moved forward or back
What is an internal biological clock?
Internal mechanism in organisms that controls the periodicity of activities
What is the photoperiod?
Day length
What is photoperiodism?
Any response of an organism to seasonal changes in day length
What is pfr?
The physiologically active form of phytochrome
What are long day plants?
Flower when the night is short, high levels of pfr
What is phytochrome?
Pigment in plants that regulates flowering
What is a circatidal rhythm?
Activity with a period of about 12.4 hours
What is a circalunar rhythm?
Activity with a period of about 29.5 days
What are phytohormones?
Plant hormones