Plant and Animal Responses Flashcards
TROPISM
Plant movement by growth. Direction of response depends on direction of stimulus
PHOTOTROPISM
Tropic movement in response to light
GRAVITROPISM (GEOTROPISM)
Tropic movement in response to gravity
CHEMOTROPISM
Tropic movement in response to a chemical
THIGMOTROPISM
Tropic movement in response to contact (eg. Climbing vine)
HYDROTROPISM
Tropism movement in response to water
TAXIS
The movement of animal towards or away from stimulus from one direction
A taxis is where an animal moves away or towards a directional stimulus.
POSITIVE CHEMOTAXIS
Movement of male moth towards female moth
HOMING
The ability to find and return to the home site
Animals return to nest on a regular basis
MIGRATION
The mass movement of organisms between two habitats (seasonal or regular)
NASTIC RESPONSE
Response to diffuse stimuli that do not come from any particular direction
Quick, non directional , done by changing turgor pressure
THIGMONASTY
Sudden closing of Mimosa leaves when touched
KINESIS
Animals only: A non-directional response to a stimulus
ORTHOKINESIS
The speed of the movement is related to intensity of stimulus
KLINOKINESIS
The amount of random turning is related to the intensity of stimulus
BIOLOGICAL CLOCK
An internal timing system which controls (to some extent) timing of activities in organisms
ZEITGEBER
External environmental cue by which an internal clock is reset.
As the onset of a zeitgeber varies seasonally, the clock is continually being reset so an organism’s activity remains synchronised with the night-day cycle
CIRCADIAN
Daily activity, approximately 24 hours (endogenous)
Difference between a circadian rhythm and a daily rhythm
Circadian = activity continues to show an approx 24-hour rhythm under constant conditions i.e. it is endogenous.
Daily = simply a rhythm with a 24-hour period; the term implies nothing about the origin of the rhythm - it may be exogenous or endogenous
CIRCATIDAL
Tidal activity period, approximately 12.4 hours
CIRCALUNAR
Monthly activity period, 29 days
CIRCANNUAL
Yearly activity period, approximately 360 days
DIURNAL
Active during the day, inactive at night
NOCTURNAL
Active at night, inactive during the day
CREPUSCULAR
Active at dawn and dusk
ARRHYTHMIC
No regular pattern found in organisms in unchanging habitats eg. caves
INTRASPECIFIC
Competition between members of the same species
INTERSPECIFIC
Competition between members of different species
Inter-house competition - between houses
HOME RANGE
Surrounds a territory; not defended and is typically an area where an animal forages for food and water if these are not supplied by their territory. Home ranges may overlap neighbouring territory holders
TERRITORY
Smaller than home range, it has defined boundaries defended from other members of the species.
PECKING ORDER/LINEAR HEIRARCHY
Occurs in a social group where the individuals are ranked from highest to lowest (from alpha to omega). The alpha individual is typically the largest or strongest male in the group.
COURTSHIP
Series of signals exchanged between male and female and ending in mating
k-STRATEGIST
Organisms who produce and care for a small number of offspring
PAIR BOND
A stable relationship between animals of opposite sex that ensures mating
PARENTAL CARE
Investment of resources by parents in the survival of offspring
PHEROMONE
Chemical used as a signal to other members of same species
MIMICRY
Adaptive resemblance between unrelated species
BATESIAN MIMICRY
Resemblance of a harmless species to one that is poisonous so reducing the mimic’s chances of predation
MULLERIAN MIMICRY
Occurs when the colourisation of unpalatable species resemble each other so reducing the chances of all unpalatable species suffering predation.
INSTINCT
Complex behaviour that is not modified by experience
CAMOUFLAGE (CRYPSIS)
Concealment method in which animal is coloured to match environment
PHOTO- PERIODISM
Regulation by activity by day length
PHYTOCHROME
Plant protein involved with the measurement of photoperiod
r-STRATEGIST
Organism which produces large number of offspring but gives them little care
Large numbers of gametes are released (an r- strategy) so that there are increased chances that reproduction will happen and some offspring will survive.
LONG DAY PLANT
Plant that flowers when day length exceeds a certain minimum value
SHORT DAY PLANT
Plants that flowers when day length is less than a certain minimum value
ENTRAINMENT
Process by which an internal clock becomes reset by rhythmic environmental factors
Occurs when an organism’s activity is synchronised with a zeitgeber e.g. onset of activity in a diurnal animal occurs at the same time as daylight begins.
FREE-RUNNING
Behaviour rhythm proceeding independently of external changes
Describes the activity of the organism under constant conditions
EXOGENOUS
Responses are controlled completely by external factors such as temperature.
Animals that are ectotherms (cold-blooded) have a core body-temperature that is controlled by the external temperature - so as the external temperature increases, do does the internal body temperature of the animal. As the chemical processes are temperature dependent, the responses of the animal tend to be faster when external temperatures are higher (typically seen in speed of movement).
ENDOGENOUS
Responses are controlled internally by an internal clock; however, the clock is set by external factors such as day-night cycle e.g. sunrise heralds the onset of daylight. These external cues are known as zeigebers.
DAY-NEUTRAL PLANT
Plant that flowers independently of day length
CRITICAL DAY LENGTH FOR LDP
Photoperiod above which long-day plants flower
CRITICAL DAY LENGTH FOR SDP
Photoperiod below which short-day plants flower
VERNALISATION
Induction of flowering by a period of chilling.
I.e. ensures a plant develops its flowers and then seeds in the spring rather than the autumn. In spring, environmental conditions are approaching maximal warmth and light intensity for optimum seed germination and growth
PRECOCIAL YOUNG
Young born in an advanced state, with eyes open
Chemical name for auxin?
IAA (INDOLE-3-ACETIC ACID)
AUXIN
Growth hormone which plays an essential role in tropisms
MERISTEM
Continuous growth area in plants (apical bud; root tip)
GIBBERELLIN
Plant growth substance that promotes elongation of shoots
KLINOSTAT
Wheel to which germinating plants can be attached and rotated
LEK
Area in which males (usually birds) congregate to mate with females
LEARNING
Behaviour that is modified by experience
NAVIGATION
Determining one’s position relative to other locations
SOLAR NAVIGATION
Using the sun to navigate
STELLAR NAVIGATION
Using the stars to navigate
Explain Migratory Behaviour
It is genetically programmed and therefore the bird has no control over the instinctive urge to migrate, inherited over thousands of years.
Territorial Behaviour
Territorial behaviour is where an animal, such as the gannet, actively defends an area where it nests and raises its young in safety.
Phase Shift
- Change in the start of activity - bring onset of preparation for activity into synchrony with onset of zeitgeber.
- Phase shifting may happen but by bit over several days
Eg - human flying through different time zones, their clock needs several days to adjust to the onset of daylight in the new time zone.
Difference between habitat and environment and niche
Habitat = The particular area/conditions the organism lives in
Environment =describes the broad condition, consisting of abiotic and biotic factor that impact an organism in its habitat.
Niche = Combination of where the organism lives (its habitat) and how it lives there (its adaptations - structural, behavioural, physiological, life cycle). The niche reflects the role that the organism performs in biological community that it is the member of
Difference between Fundamental niche and Realised niche
Fundamental niche, typically set by abiotic factors (and an organism’s ability to tolerate these factors) is the niche an organism would occupy if all the environmental factors needed were present.
Realised niche, typically set by biotic environmental factors (esp interspecific competition) is the actual nice an organism occupies.
Parasitism
a (symbiotic) relationship where one animal / organism benefits and the other animal / organism is harmed.
Free-running period
Length of activity under constant conditions. With no zeitgeber to set the clock and hence to set the start of activity, the start of activity tends to move forward or backwards each day.
The time from onset one day to onset the next day gives the free-running period.
This may be more than 24hours (activity moves forward each day) or less than 24hours (activity moves backward each day).
Abscission
Seasonal fall (autumn) of leaves in deciduous trees.
Abscission stops transpiration. As ground water in winter freezes, not possible to replace war lost in transpiration with soil water. Therefore, abscission prevents water loss from plant, so preventing the plan tissues from dying out (desiccation), which can lead to death.
Diapause
Seasonally induced pause of growth and development in arthropods (insects, spiders etc) eg crickets
It helps an organism avoid a period of unfavourable environmental conditions so avoiding likely tissue damage or death
Stimulus: a decrease in day length at the last larval stage (adult-eggs-larva-pupa-adult)
Hibernation refers to decrease in metabolic rate in mammals
Hibernation
A period of suspended activity during winter (true hibernation is psychologically prepared for e.g. laying down of fat).
It enables animals to survive cold winter conditions in areas of low temperatures and little to no food, reduced habitat (trees are deciduous) preventing possible death from hypothermia and/or starvation.
Orthokinesis
Animal’s rate of movement determined by the stimulus.
Klinokinesis
Animals’ rate of turning is determined by the stimulus
Difference between radicle and plumule and shoot
Radicle: embryo root that emerges from a germinating seed
Plumule: embryo shoot and leaves that emerge from a germinating seed
Shoot: the above-ground parts of a young plant (stem, leaves etc)
Describe how IAA is involved in the gravitropic response of plumule and radicles
IAA accumulates on the lower sides of the plumule and radicle (side closest to source of gravity). High concentrations of IAA on this side stimulate cell elongation in the plumules, so the plumule grows upwards but inhibits cell elongation in radicles so the radicle grows downwards.
Commensalism
It is a relationship between two species in which one benefits while the other is not harmed
Mutualism
It is a relationship between two species in which both benefit
Predation
It is the relationship between a predator and a prey species in which the predator kills and eats the prey
Parasitism
It is a relationship between two species in which one lives and feeds off another living species (the host) - the host is harmed, but not killed, in the relationship
Difference between ectoparasites and endoparasites
Ectoparasites live on the outside or skin of the host, typically feeing from the host’s blood using piercing and sucking mouthparts.
Endoparasites live inside the host, typically in part of the blood or digestive system of the host
Herbivory
It is the relationship between animals (mainly) and plants in which the herbivore eats part of the plant (doesn’t kill it).
Stratification
Vertical layering of plant (start), typically seen in a forest community
Zonation
Horizontal life bands that occur as an environmental factor changes (e.g. water exposure on intertidal shore, temperature with altitude on mountains).
Difference between Primary succession and Secondary succession
Primary succession occurs on bare land that has not been previously inhabited.
Secondary succession occurs when previously i habituated land has been cleared by a catastrophic events such as landslips, earthquakes, fires or floods.
Succession leading to the development of a mature biological community is faster with secondary succession, as some fertile soil is still present.
Exploitation
The relationship between two species in which one benefits while the other is harmed; includes parasitism, herbivory, predation
Co-evolution
Occurs when two species with a strong ecological relationship influence each other’s evolution, each exerting selection pressure on the other
Adaptive advantages of territorial behaviour
- Territorial behaviour ensures greater reproductive success due to better mating success (attraction or reconnecting with mates) and greater focus on parental care, resulting in greater fitness of the young.
- Territoriality results in the fitter pairs producing genetically fitter offspring and survival of stronger genotypes and phenotypes.
Adaptive advantage of the nastic response where leaves droop at night
- Allows plant to reduce its leaf surface area at night so there’s less chance of damage due to exposure to colder temperatures and may lead to less frost exposure on cold nights.
- Heat can be conserved.
- Collection of night-time moisture onto lowered leaves will lead to water being channelled onto the ground where it can be absorbed by the roots. In the case of flowers, closure at night can keep pollen dry, as dry pollen will stick better to pollinators than wet pollen.
- Lowering leaves and closure of flowers means less chance of damage by nightime predators, especially loss of pollen.
Advantage of endogenous clock
The endogenous rhythm has an adaptive advantage, ensuring the squirrel becomes active at nightfall without needing to go out during the day when visible to predators, or staying inside and missing nightfall and the chance to feed under reduced light when most food is available and it is safest from predators. Energy is conserved, as squirrels are active only when they need to be.
Explain the role of auxin
Once the shoot has germinated, auxin produced in the shoot tip settles on the lower side of the shoot and causes cells to elongate, whilst cells on the upper side continue to grow normally. This causes the shoot to bend in an upwards direction and ensures the shoot grows up to the surface and shows a –ve gravitropic growth response.
When the shoot breaks through the soil surface, auxin produced in the shoot tip / apical meristem accumulates on the shaded side and causes cell elongation, whilst the non shaded cells grow normally and differential growth occurs so that the shoot bends towards the light and shows a +ve phototropic response.
Adaptive advantage of positive gravitropic response of root
Anchorage and water
