Surface area to volume ratio Flashcards
what types of substances can be exchanged
oxygen + nutrients taken in
CO2 + urea secreted
heat to stay at roughly same temperature
ways in which substances can be transported
active transport
passive transport
smaller animals will have a …sf area: volume ratio
higher
why can’t direct diffusion be used for multi-cellular organisms
- too slow
- cells too far away from exchange surface
how are substances exchanged in multi-cellular organisms and why
mass transport
as larger animals have lower sf area : volume ratio
how are substances exchanged in single-celled organisms and why
substances diffuse directly
- small distance of travel
a small distance of travels allows for a
quicker rate of diffusion
what 2 things does mass transport maintain
final concentration gradients
relatively stable environment
the rate of heat loss depends on
surface area of organism
how does being a larger animal affect heat loss and why
larger animal = larger volume, smaller surface area
harder to lose heat
how does being a smaller animal affect heat loss and why
smaller volume so larger surface area
heat is lost more easily
how is heat loss compensated for in smaller animals
higher metabolic rate
to generate enough heat to stay warm
how would having a compact shape benefit a smaller animal
smaller sf area
minimises heat loss
what is a compact shape dependent on
temperature
environment
how would a less compact shape affect an organism
greater sf area : volume ratio
increases heat loss
