exchange surfaces Flashcards
3 factors that decide if an organism needs a SES
surface area:volume ratio
metabolic rate
size
list substances organisms need
oxygen, water, glucose, amino acids, lipids, mineral ions
small unicellular organisms have a _____ SA : V ratio and a ____ metabolic rate
very large, low
small unicellular organisms rely on ______ to obtain substances
diffusion
large multicellular organisms have a _____ SA:V ratio and a _____ metabolic rate
small, high
large multicellular organisms rely on ______
specialised exchange surface
large multicellular organisms have ____ heat loss
slow
smaller animals, e.g rats have a _____ SA:V ratio than larger animals and have a _____ metabolic rate
larger, high
smaller animals have _____ heat loss
rel. fast
smaller animals rely on _____ to obtain substances
specialist exchange surfaces
very small animals e.g leech have a _____ SA:V ratio and have ____ skin
v. large, moist
very small animals e.g leech have some _____ _____ through _____ _____
gas exchange, moist skin
what is ficks law
rate of diffusion;; SA x conc difference/ thickness of membrane
define ficks law (words)
relationship between variables that affect diffusion
factors that make a good exchange surface
large SA
thin/short dd
steep conc gradient
-fresh supply and constant removal
