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50 terms

Biology Plant responses and Animal Behaviour

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abiotic factors
physical factors in the environment which can act as a stimuli for the organisms' responses
tolerance
the range of physical factors which are favourable for the organism
biotic factors
biological influences on organisms within an ecosystem
stimulus
change in environment which causes a response in an organism
receptor
any cell or group of cell which detects a change in stimuli
effector
a cell or group of cells which respond to change
interspecific
relationships between different species
intraspecific
relationships between organisms in the same species
ecosystem
all things living in a particular area including physical factors
habitat
he place or environment in which specific organisms live
limiting factor
any variable factor which limits the activity of an organism or population
gause's principle
no two species with identical ecological niches can co-exist for long in the same place
ecological niche
the way an organism lives
biological clocks
Internal timing systems that continue without external clues, and control (to some extent) the timing of activities of plants and animals.
period of the rhythm
the time it takes to complete one cycle of activity
phase shift
a shift in the activity of a biological rhythm, typically provided by a synchronizing environment stimulus
free running period
The natural period of the rhythm if there are no external cues.
entrainment
Process by which an internal clock becomes reset by rhythmic environmental factors
zeitgeber
the environmental agent that resets the biological clock e.g: change in light, temperature
circadian
of or relating to biological processes occurring at 24-hour intervals
circa
about
circatidal
A rhythm of about 12.5hours
circalunar
A rhythm of about 1 month
circaannual
A rhythm of about 1 year
photoperiod
the response in animals and plants to the length of the day and night
exogenous rhythm
A rhythm that continues only when external cues are present.
endogenous rhythm
An internal rhythm that occurs when there are no external cues. Caused by a biological clock
tropism
the growth response of a plant toward or away from a stimulus
nastic movement
a plant's response to a stimulus such that the direction of the response is preprogrammed and not dependent of the direction of the stimulus
taxes
movement of a whole organism towards or away from a stimulus
kinesis
a non-directional response to to a stimulus - animals
homing
Ability of an animal to find its way home over unfamiliar territory
auxin
substance produced in the tip of a seedling that stimulates cell elongation
apical dominance
Concentration of growth at the tip of a plant shoot, where a terminal bud partially inhibits axillary bud growth
cytokinins
Concentration of growth at the tip of a plant shoot, where a terminal bud partially inhibits axillary bud growth
gibberellins
a growth hormone that causes a wide variety of effects. One role is to stimulate growth of stems by promoting cell division. Farmers use it to make fruit grow larger
apical meristem
the growing region at the tips of stems and roots in plants
ethylene
hormone that promotes leaf abscission and fruit ripening
abscisic acid
hormone that promotes bud and seed dormancy and inhibits leaf abscission
etiolation
the act of causing a plant to develop without chlorophyll by growing it without exposure to sunlight
short day plants
plants that bloom only when the period of daylight is shorter than a specific period of darkness
long day plants
plants that bloom only when the period of day is longer than a specific period of darkness
day neutral plants
A plant in which flowering can occur irrespective of the day length
phytochrome
pigment used to measure time
vernalisation
Exposure of seeds to a period of cold to break the seeds' dormancy
dormancy
a period when an organism's growth or activity stops
stratification
when a moist seed is exposed to a low temperature for many days to break dormancy
scarification
the process where seeds need to be scratched or treated in a rough way before it can germinate
ephemerals
a chemical present in desert plants which prevents germination unless there is sufficient ain which washes the chemical away
abscission
shedding of flowers and leaves and fruit following formation of scar tissue in a plant