Sub 10: Conformers and Regulators Flashcards
what do we call the ability of organisms to maintain a constant internal environment in the face of constant changes in the external environment?
homeostatis
what is stress?
physiological condition where the level of an environmental condition or resource is outside the optimum range for that organism
what are the adaptations for organisms living with constant wave action?
strong means of attachment - holdfasts
physically resistant body structure - shell
behavioural - settle in cracks between rocks
what are the adaptations for organisms living in the arctic and antarctic habitats?
large body size to give small surface area to volume ratio to reduce heat loss through radiation
thick coat and layer of blubber
white coat to blend into environment
what is vasoconstriction?
when surface capillaries constrict and get narrower
what is vasodilation?
capillaries dilate for rapid heat loss
why does a plant wilt?
cause the leaf surface to be removed from direct sunlight and can prevent plant overheating and reduce transpiration rate
what is a regulator?
regulators are able to maintain their internal environment regardless of the changes in the external environment
why do regulators require more energy than conformers?
regulators use up a lot of energy in maintaining their internal environment so more food is required more frequently
conformers have more energy available fro growth and reproduction
do regulators or conformers have greater freedom of movement?
regulators as they are least affected by environment temperature
what are conformers?
conformers do not maintain a constant internal environment, it changes with the external environment
what is osmoregulation?
mechanism by which organisms maintain a constant water balance within their cells
give examples of osmoconformers
shrimp, crabs and jellfish
what are osmoconformers?
their body fluids are isotonic with their environment
what are osmoregulators?
body fluids are not isotonic with the environment
what are poikilotherms and homeotherms?
poikilotherm - body temperature varies with the surrounding environment e.g. snake
homeotherm - maintain a constant body temperature e.g. humans
what is body temperature monitored by
the hypothalamus in the bottom of the brain
what is temperature changes detected by initially?
nerve cells in the skin
what are behavioural methods of thermoregulation?
resting in s cool burrow to avoid the heat of the day
migrating
basking on rocks to absorb heat from sun
cooling down in water
what is dormancy?
a period when the organisms metabolism is reduced promoting survival during adverse conditions
what is predictive dormancy?
allows dormancy to occur before the onset of adverse conditions in habitats where the change occurs in a regular way
what is consequential dormancy?
allows the organism to react immediately to environmental cues. organism enters a state of dormancy after they have been exposed to adverse conditions
what is the disadvantage of consequential dormancy?
sudden changes in conditions may result in high mortality rates
what is the advantage of consequential dormancy?
dormancy is delayed until adverse conditions arise, meaning that the organism can make use of the resources available in the habitat for as long as possible
name all types of dormancy
torpor diapause hibernation aestivation resting pores
what is torpor?
reduction in body temperature to an ambient temperature when inactive during the day
what is diapause?
predictive dormancy - suspension of development in insects.
what is hibernation?
period of longterm inactivity in animals. lower metabolic rate
what is aestivation?
consequential dormancy entered into by organisms in response to very hot, dry conditions
what are resting spores?
consequential dormancy - when hard cases surrounds the dehydrated content of the seed or spore
describe the tolerance curve
there is an optimum range within which the performance of the organism reaches a maximum.
between the upper and lower limits, the performance decreases
beyond the limits the organism cannot survive
what is the clutch size?
the number of offspring produced at each reproductive episode
what is the differences between r and k selected species?
r selected - rapid development, small adult size, many small offspring, short generation time
k selected - slow development, large adult size, few, large offspring, long generation time
why are r and k selected species the way they are?
r selected are adapted to maximise the rate of increase of population size
k selected are adapted to be competitive
what is a survivorship curve?
expresses the age distribution of a population and can be used to predict future population numbers
