lesson 15 surface area to volume ratio Flashcards
amoeba are what
single-celled organisms
single-celled organisms can rely on diffusion to do what
transport molecules in and out of their cell
as organisms get larger what happens to the surface area: volume ratio
it falls sharply
surface area: volume falling as organisms get larger is a huge problem for which
multicellular organisms
what are multicellular organisms
organisms with more than one cell
multicellular organisms surface area is not what
large enough for its volume
cells on the surface can get enough oxygen simply by diffusion however what
not enough oxygen can diffuse into the cells into the cells in the centre of the organism as they are too far away from the surface
animals have got what to help oxygen diffuse to the centre of the organism
they have special structures for gas exchange with a very high surface area
(eg lungs in mammals)
what’s another way animals help oxygen diffuse to the centre of the organism
they have a transport system to carry gases around the body
where do the fish get their oxygen
from the water
which type of water passes into the fish’s mouth
the oxygen-rich water
the oxygen-rich water then flows where
into the gills, where the oxygen is transported into the blood stream
the gills are covered in a very large number of what
fine filaments
what do the fine filaments do
this is where gases pass in and out of the blood
deoxygenated blood passes where
into the filament
