Plant responses
This plant hormone causes cell elongation in shoots and is responsible for directional growth responses like phototropism
Auxin
A directional movement of an animal towards or away from a stimulus, such as a woodlice moving away from light
Taxis
An external environmental time cue (like sunrise or temperature change) that resets or synchronizes an organism's internal biological clock.
zeitgeber
An area used by an animal or group for feeding or breeding that is actively defended against intruders
territory
A reversible, non-directional plant movement response triggered by a change in an abiotic factor, often involving changes in turgor pressure.
Nastic response
A non-directional animal movement response where the speed of linear movement depends on the intensity of the stimulus
orthokinesis
Biological rhythms that cycle with a period of approximately 24 hours
circadian rhythm
A mating system where an individual has only one exclusive mate for a breeding season or life, increasing parental care investment
monogamy
The directional growth movement of a plant part in response to a chemical stimulus, such as pollen tubes growing down the style.
Chemotropism
The innate ability of an animal to find and return to its specific home site or nest across unfamiliar terrain
Homing
This term describes a biological rhythm when it continues to run in constant, unchanging environmental conditions, free from any external time cues
free-running
Behavior that reduces an individual's own immediate fitness or survival chances while increasing the reproductive success or survival of other relatives
altruism (or kin selection)
This pigment exists in two interconvertible forms (Pr) and (Pfr) and controls the photoperiodic flowering response in plants.
Phytochrome
A type of taxis where an organism determines the direction of a stimulus by alternately comparing signal intensity from side to side using receptor cells while moving
Klinotaxis
The process of resetting an internal biological clock using rhythmic environmental synchronizers so it matches local time
entrainment
This specific type of display involves ritualised, non-lethal combat or body postures used by animals to establish rank within a hierarchy without causing serious injury.
agonistic behaviour
The ecological phenomenon where a plant produces and releases chemical inhibitors into the environment to suppress the germination or growth of neighboring competing plants.
Alleopathy
Navigational compass mechanism that allows migrating animals (like birds) to maintain a constant angle relative to the sun regardless of the time of day
If an animal's activity cycle begins 18 minutes earlier each day under constant laboratory conditions, this is its calculated free-running period (assuming a baseline 24-hour day).
23 hours and 42 minutes (24hrs - 18mins)
The ecological principle stating that two species competing for the exact same limiting resources cannot stably coexist in the same niche
Gause's Principle