3.3 Biology ncea

abiotic

abiotic

Non-living, environmental aspects

abscisic acid

inhibits bud growth and promotes abscission zone formation

abscission

the act of cutting; the natural separation of a leaf or other part of a plant. Due to breakdown of cell layers at their base.

Adaption

inheritable structural, behavioral, or physiological features that increases survival/reproduction

Aestivation

Dormant state that helps an animal withstand extreme temp periods

aggression

belligerent behavior intended to hurt or destroy

Allelopathy

The production of chemicals by plants that inhibit the growth of neighbouring plants

alpha animal

Most dominant individual

Annuals

A flowering plant that completes its entire life cycle in a single year or growing season.

Antibiosis

association between organisms which is injurious to one of them

apical dominance

Tendency for growth to be concentrated at the tip of a plant shoot, because the apical bud partially inhibits axillary bud growth.

apical meristem

area at tip of plant root/stem that produces auxin and is origin of growth/site of mitosis

Auxin

a plant hormone that promotes root formation and bud growth

Batesian mimicry

A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators.

behaviour

responses, actions, or movement made by an animal

biennial

happening every two years

biological clock

An innate mechanism in living organisms that controls the periodicity of many physiological functions.

ecological niche

the role of a species in its habitat, its biotic and abiotic resource requirements

Elongation

lengthening of a cell prior to division, allows growth to be directional

Endogenous

behaviors caused by internal factors which are independent of external stimuli

Entrainment

the process of resetting the internal clock by synchronizing it with an external environmental cue

environment

all of the external factors affecting organisms, both internal and external

ephemerals

plants with a very short lifespan that take advantage of brief favourable conditions, e.g. flowering plants in a desert

epiphytes

a plant growing on another plant, no obtaining nutrients from it, non-parasitic

ethology

the study of animal behaviour

ethylene gas

a plant hormone regulating fruit ripening, abscission, growth and ageing

etiolation

plant condition of excessively long, weak stems (internodes) and small leaves due to lack of light, yellow colouration

exogenous

caused by external stimuli

exploitation

any relationship between species which enhances the fitness of one specices while decreasing the fitness of the other

facultative relationship

type of relationship where the survival of the organisms involved is not reliant upon the relationship

florigen

the plant hormone which is produced in leaves and travels to a shoot axis to trigger flowering

free running

biological rhythm which persists in consistent environmental conditions

gause's principle

two species in the same habitat cannot permanently occupy the same niche/utilize the same limiting resource

gibberenllins

group of plant hormones which promote stem elongation, leaf growth, and other processes

herbivore

animal which consumes only plant material as its source of nutrition

Biotic

aspects of an environment due to the presence of living organisms

chemotropism

growth response of a plant in response to a chemical concentration gradient

circadian

rhythm of behaviour or intensity which cycles over an approx. 24 hour period in normal environmental conditions

circalunar

rhythm of behaviour or intensity which cycles over approx. 29 days in normal environmental conditions

circaannual

rhythm of behaviour or intensity which cycles over an approx. a year under normal environmental conditions

circatidal

rhythm of behvaiour or intensity which cycles over an approx. 12.4 hours under normal environmental

coleoptile

protective sheath covering the shoot of grass seedlings

commensalism

relationship between two species where one benefits and the other is neither harmed or benefitted

competition

occurs when demand for a resource from organisms in an area exceeds supply, both organisms are negatively affected

co-operation

members of a species co-ordinate activities for their mutual benefit

crepuscular

active at dawn and dusk

cytokinins

any of a group of plant hormones which retard ageing, promote budding and cell division and breaking dormancy

day neutral plants

plants which begin flowering at a certain age rather than in response to day length

diapause

a delay in some stage of an arthropods' development

Diunrnal

active during the day

divarication

forking growth pattern in plant branches as a defense against herbivores

dominant

animal at the highest level of dominance in hierarchy, usually maintained by agonistic behaviour

dormancy

state of temporarily reduced metabolism and a subsequent lack of growth and activity

hibernation

period of dormancy during seasonal cold conditions

hierarchy

social order in an animal group where one animal is dominant over another (others)

home range

area where an animal or group of animals seek food but do not generally defend

homing

innate ability of an animal to navigate through unfamiliar areas to an original location

hydrotropism

growth response of plant roots in a particular direction in response to the presence of water

IAA

indol acetic acid - auxin, plant growth hormone, causes cell elongation, promotes cell growth and differentiation

innate

behaviour which is coded in DNA rather than learned, usually exhibited by all members of a species

interspecific

relationship between members of two or more species

intraspecific

relationship between members of the same species

kinesis

non-directional response of an animal to a stimuli, usually relates to rate of movement or frequency of turning

lateral buds

an embryonic shoot which is situated at the junction between a stem and a leaf

legumes

pod-bearing plants that have root nodules containing symbiotic nitrogen fixing bacteria

lianas

a climbing plant

long day plants

plants that begin forming flower buds when sunlight hours exceed their critical period

migration

a regular mass movement of individuals over long distances, usually on a seasonal basis

mimicry

a method of avoiding predation by camouflaging, resembling other species that are harmful, either batesian or mullerian

mullerian mimicry

several unpalatable species resemble eachother

mutualism

close relationship between two species from which both benefit, a form of symbiosis

nastic

non-directional movement response of a plant organ to the intensity of an environmental stimulus

neutrality

organisms in the same place and time whose presence has little/no effect on each other

obligate

an organism or relationship that is required to function in that way for survival, e.g. obligate parasite can only live parasitically

over-wintering

range of processes including hibernation, migration and dormancy by which organisms pass through winter conditions.

pair bonding

development of a social bond between the male and female of a monogamous pair

perennials

plants which continue to flower for several years

phase shift

shifting the start time of a rhythm due to a change in environmental conditions

pheromones

chemical released by an animal which influences the behaviour of other members of its species.

photoperiod

the number of daylight hours - changes throughout the year in seasonal environments

phototropism

directional growth response of plants in response to the direction of light

physiological tolerance

the range of values of an abiotic factor that an organism can survive in

phytochrome

the blue-green protein pigment found in most plants which acts as the light receptor for several processes

plant hormone

chemical in a plant which results in a response by other cells in the plant

predation

members of one species kill/eat members of another species

scarification

damage to seed coat required for germination

seed masting

synchronized production of large volumes of seeds within a population of plants

short day plants

plants that begin forming flower buds when sunlight hours are shorter than their critical period.

stimuli

an aspect of the environment which causes some responses, detected by a receptor or sensor

stratification

the vertical pattern of species distribution seen in a community

submissive behaviour

behaviour which reduces aggression from a dominant individual and reinforces the lower status of another

subordinate

animal at a lower level of hierarchy

symbiosis

organisms from different species living in long-lasting and dependent relationships in which at least one participant benefits

taxes

movement of an animal in response to a directional stimulus either towards or away from it

territory

area defended by an animal, usually from animals of the same species

thigmotropism

growth response of plants in response to an object or contact with it

tropism

plant growth in response to the direction of an environmental stimulus, either towards or away from

vernalisation

exposure to cold temperatures that enables or accelerates flowering in some plants, or is needed for seeds to germinate

waggle dance

communication behaviour in bees to direct other forages to a food source

zietgeber

an external environmental cue used to synchronise rhythmic behaviours with external environmental conditions/rhythms