Adaptation for arid environments Flashcards
what is the key challenge for organisms in arid environments
avoiding excessive water loss that can result in dehydration and overheating which can cause hyperthermia as well
SA:V in desert animals
big animals (elephants/camels) have low sa:v so heat up slowly and have ways to insulate or radiate. small animals avoid the heat or have large ears (e.g) to release heat
how do humans and mammals lose water
kidney and urine production, lungs in exhaled breath, gut and waste production, the skin and water lost through pores (perspiration)
how do mammals increase their water levels
drinking water/other fluids and water ingested in food and its produced during aerobic cellular respiration
what is topor
when animals allow their body temperature and metabolic rate to drop and become inactive for a period of time
how and what is topor/ hibernation an adaptation
behavioural - going into a burrow, physiological - slowing metabolism and reducing the amount of energy required
what is dormancy
a period of an organisms life where its growth, development and physical activity are temporaraly stopped
how does a long nose help animals that live in arid nevironment
as warm humid air passes over the membranes lining the nasal passage, it is cooled and water condenses on the membrane instead of being breathed out
what does a long loop of henle do
it allows animals to concetrate their urine and take more water back into the bloodstream
obvious adaptation of arid environments in plants
thick, waxy cuticle, hairs covering leaves, few stomata, sunken stomata, reduced leaf SA:V, leaves not facing direct sunlight, opening stomata at night, deep or wide roots
how does a thick waxy cuticle prevent over heating
it acts as a barrier to evaporation and the shiny surface rreflects heat
hairs help water loss how in ariid
help to store or capture water, expand sa:v
how does a sunken stomata prevent water loss
increases the hunmidity of surrounding air, water gradient is less
how do spread out roots help to gain water
as soon as there is rain fall, the roots can take up all the water from the surface
how to deep roots help water gain
the roots can go deeper underground where water may be
