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Plant and Animal Key Words

WORD

DEFINITION

Abscisic Acid

A plant growth hormone that has a variety of effects

Actogram

a type of graph or chart commonly used in circadian research to plot activity (present or absent) against time

Agonistic

Intraspecific behaviour that alternates between attack and escape

Antagonist

Something opposing or in conflict with another

Auxin

A plant hormone regulating growth by effecting cell elongation

Biological Clock

the set of mechanisms within living organisms that link physiological processes with daily, monthly, or seasonal cycles or with stages of development and ageing

Biological Orientation

 the change in position of the whole or part of an organism in response to a stimulus, such as light.

Chemo-

Being effected by a chemical

Circadian

A cyclical variation (rhythm) that lasts approximately 24 hours under constant environmental condition

Circannual

A cyclical variation (rhythm) that lasts approximately a year under constant environmental condition

Crepuscular

Most active at dusk and dawn

Critical Day Length

The photoperiod above which long-day plants flower and below which short day plant flower

Cytokinins

A group of plant hormones retarding ageing, promoting cell division and bud formation, sometimes promoting flowering and breaking dormancy

Diapause

A delay at some stage in the development of an arthropod, caused by stimuli indicating a change in environmental conditions and ended by specific stimuli

Diurnal

Most active during the day

Dormancy

A state of temporarily reduced metabolism

Effectors

A cell or organs that responds to a stimuli

Endogenous

Caused by internal factors that are independent of external stimuli

Entrainment

The process of resetting an internal clock so that it is synchronised with environmental rhythms

Exogenous

Caused by external stimuli

Free-running

A rhythm is free-running when it is proceeding independently of external changes

Geo-

Caused by gravity

Geomagnetic Cues

Using the earths’ magnetic field for orientation

Hibernation

A period of dormancy of animals during seasonal cold conditions, generally to survive a lack of food

Homing

The ability of an animal to find its way home over unfamiliar territory

Hormones

Chemical secreted into a plant or animal and transported to another part where it affects growth or activity

Innate

Coded for by genes

Kinesis

An orientation movement of an animal in which the stimulus governs the rate, but not the direction of movement

Learned

Behaviour that is modified by experienced

Long Day Plant

A plant that flowers when day-length exceeds a certain minimum length

Migration

The regular mass movement of members of a species for breeding and back again

Mimicry

The similarity in appearance of one species of animal to another that affords it protection from predators

Nastic Responses

Response of a plant organ to a non-directional environmental stimulus

Nocturnal

Most active at night

Optic Lobes

Part of the brain that contains primary visual centers

Ortho-/Klino Kinesis

Orientation responses in which the strength of the stimulus controls the rate of linear movement (ortho) or rate of turning (klinoO

Phase Shift

A phase of a rhythm is shifted so that entrainment occurs

Photo-

Response to light

Phytochrome

A pigment found in most plants that acts as the light receptor

Pigment

a natural substance in plant or animal tissue that gives it its colour

Pineal

Small gland at the top of the brain stem that secretes a hormone

Polyandry

The practice of a female mating with more than one male in a breeding season

Polygamy

The practice of random mating with more than one member of the opposite sex during a breed season

Polygynandry

An organised social system in which during a breeding season a female mates with several males and a male mates with several females within the social group

Polygyny

Occurs when a male mates with more than one female

Receptors

A cell or organ able to detect changes in the environment

Short Day Plant

A plant that flowers when day-length is less than a certain minimum length

Star Compass

Using the stars to navigate

Stimulus

An aspect or change in an individual’s external or internal environment that causes some sort of response

Sun Compass

Using the sun to navigate

Taxes

Directional movement in an animal towards or away from a stimulus

Thigmo-

Response to touch

Tropisms

A plant growth response to an external direction stimulus causing the plant to curve towards to away from the stimulus

Zeitgeber

An external environmental cue used to synchronise rhythmic behaviours with external events

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