lecture 4 Flashcards
all individuals must solve some basic problems which are?
- acquire energy, nutrients, or resources neccesray to grow and develop
- must survive to reproductive age
- acquire energy, resources, or mates necessary to reproduce and rear offspring
why are ecology of individuals solutions difficult?
- because of large number of environmental factors affecting survivorship, growth and reproduction
- enormous variation in these factors in time and space
what is physiological ecology?
the study of the biophysical, biochemical and physiological processes used by plants and animals to cope with factors of their physical environment or employed during ecological interactions with other organisms
what are the two types of abiotic factors?
- resource
- condition
what is the resource abiotic factor?
an abiotic factor that is consumed by an organism or made less available to others (food, water, space)
what is the condition abiotic factor?
an abiotic factor that varries in time and space and to which organisms respond differently (temperature, salinity, humidity)
why is temperature so important in ecology?
because organisms have evolved a multitude of mechanisms for regulating the temperature of their bodies in order to flourish in their particular environment
why is water availability so important in ecology?
because the bodies of all organisms contains water and all environments expend energy to maintian their internal pool of water and dissolved substances
what is a poikilotherm?
body temperature fluctuates with ambient temperature of environment
what is a homeotherm?
maintain relatively constant body temperature despite changes in environmental temperature
what is a heterotherm?
a mix of poikilotherm and homeotherms –> two types (ectotherm and endotherm)
what is an ectotherm?
an organism that regulates body temperature by selecting appropriate thermal environments
what is an endotherm?
an organism that regulates body temperature by using internal metabolic processes
what is torpor?
when animals that normally maintain a high body temperature permit it to drop under certain conditions
what does ct stand for?
critical temperature
what does Lt stand for?
lethal temperature
what are the limits in a thermal performance curve?
- dynamic using CTmax and CTmin
- static using upper and lower Lt50
what does performance correlate to?
fitness
what do we see during low temperature on thermal performace curves?
low critical thermal limit means that at some point an organism will freeze to death but some can recover
what happens in an organism at low critical temp?
- extracellular fluids freeze and cells burst
- slowed muscle contractions
- slowed ATP production
-decline in nervous function
what do we see during high temperature on thermal curves?
- reduction in metabolic efficiency
- oxygen limitation and fermentative metabolism (o2 supply is maximized, fermentative ATP production is less effective)
- cellular stress: heat shock
