Biology 3.3 Key terms: Plant and Animal Responses

A biological rhythm synchronised to the lunar cycle, occurring monthly.

An area defended by an animal.

A growth response towards or away from an environmental stimulus coming from one direction.

Plant that flowers when exposed to dark periods of less than a critical length.

The shifting of a period of activity from one particular time to another. 

An interspecific relationship in which an individual benefits at the expense of a host 

The period of an endogenous rhythm when given no external environment cue. 

An interspecific relationship where organism benefits and the other is unaffected

An exogenous cue that synchronises endogenous rhythms to the environmental rhythms.

An endogenous rhythm with a period of entrainment that approximates the lunar cycle.

The synchronisation of an endogenous rhythm with an external cycle such as light and dark.

Plant growth hormone which plays a role in the tropisms of stems and leaves.

Organism that is active mainly during the night.

A rhythm or cycle occurring on a yearly basis.

Growth of a plant towards or away from light.

An environmental stimulus that is external to the organism is referred to as this.

A biological rhythm synchronised to the tidal cycle, occurring about every 12h. 

An area an animal uses for food, but is not defended.

Diagram showing the periods of activity and rest of an organism over a number of 24h periods. 

The physiological reaction of plants and animals to the presence and absence of light. 

Plants that require a period of dark exceeding a certain length. 

Condition caused by asynchrony between the endogenous circadian rhythm and the external cues. 

Non-directional response of an organism

A plant that flowers independently of the day length or seasons.

Environmental stimulus used by animals and plants to establish & maintain an activity pattern.

Mass movement of individuals at regular intervals, often over long distances.

A pigment in plants responsible for the photoperiodism effect. Regulates flowering timing.

An organism that is active during the period of daylight. 

A period of activity and rest that repeats around every 24h.

An organism that is active during the periods of dawn and dusk. 

A stimulus originating within the organism itself is called this.

Plant movement in response to a stimulus that is not dependent on the direction of the stimulus

The ability of animals to find and return to their home site.

Directional orientation due to receptors comparing the lateral intensity of stimuli 

Growth of a plant towards or away from light

Orientation responses in which the strength of the stimulus determines rate of linear movement

Physiological or activity changes in living organisms occurring in a cyclic manner. 

An endogenous rhythm with a period of entrainment that approximates the tidal cycle.

An endogenous timing system to synchronise an organism's activities with the environment.

Direction of movement depends on direction of the stimulus