Taronga Zoo Exam Flashcards
what is vasodilation?
process which dierts the flow of heated blood to the skin of the animal, where heat can be easily released into the environment
what is vasocontriction?
vasocontriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels
flow of blood is restricted and decreased, less blood reaches the surface, reducing the radiation of heat
what is a structural adaptation?
teh physical features of an organism
what is a physiological adaptation?
chemical changes in the body
what is a behavioural adaptation?
things an organism will do to survive
why must an organism maintain its water content?
- living cells work best in an isotonic environment, conc of solute the same as inside and outside the cell
- conc of water effects enzyme-subtrate interactions ; conc to dilute, insuffiecient interactions
if subtrate is too conc, insufficient water to carry out metabolism and waste con becomes higher, effecting ph and enzymes in a negative wat
- cells could shrink or explode
- temp stays relatively constant in organisms who have adequate amounts of water; high specific heat capacity
what are some adaptations of the koala in thermoregulation and water retention
behavioural
- will push out from tree to cool down and curl up closer to the tree to retain heat
- nocturnal to escape the heat of the sun
Structural
- fur and fat for insulation from the cold
- small ears to minimise heat loss through small SA
- no sweat glands, maximises presevation of water
Physiological
- highly concnetrated urine and dry feaces; mimisies water loss
- small brain makes sure little energy is required, low energy diet
why do koalas have to retain alot of their water?
because they obtain their water content from eucalyptus leaves, which is very low in water, 400ml a day
is a koala a endotherm or ectotherm?
endotherm
