Conformers and regulators Flashcards
Organisms are affected by abiotic factors. What are abiotic factors?
non-living components of the ecosystem such as water availability, salinity, temperature, other atmospheric conditions.
Abiotic components affect species in a density-independent way. What is meant by density-independent?
The change in size of the population is unrelated to the number of organisms in the area.
what happens is the conditions in a habitat vary slightly from a species’ optimum conditions and what happens when they are far from the optimum?
Slightly: reduces population size in density-indipendent way.
Far: the health of individuals is reduced.
What are the two strategies in organisms to allow them to survive through changing environments?
Conformation and regulation.
What happens to organisms which conform?
Conformers allow their internal physiological variables to fluctuate directly with the changes in their external environment.
Osmoconformers? Poikilotherms?
1: organisms which allow their water concentration to be the same of that of their surroundings.
2: organisms whose body temperature is the same as their surroundings.
what is “tolerance”
The ability to still function as an organism although the environment changes.
HOw is tolerance possible?
Only over a narrow range of conditions, otherwise the organisms become stressed.
What is “resistance”?
Conformers having adaptations which isolate them from environmental change.
What is avoidance behavior?
Behavior that allows conformer organisms to cope in unfavorable habitats.
What organisms use regulation strategy?
Organisms that use homeostatic mechanisms to maintain a constant internal environment despite changes in the external environment..
What is the result of homeostasis?
More metabolic processes=higher energy costs.
Using regulation strategy organisms can colonise a wider range of environments.
What is dormancy?
A period when an organisms metabolism is reduced, promoting survival through adverse conditions.
The active reduction in the metabolism is due to genetic mechanisms and is not merely a slowing down of enzyme activity due to colder temperatures(!)
Why does dormancy occur?
Some habitats have long term changes in their abiotic conditions that are too great for the organisms to survive.
What is the difference between predictive and consequential dormancy?
Predictive: happens before the onset of adverse conditions (happens when the changes are periodical).
Consequential: starts after the onset of adverse conditions.
