3.3.1 Surface Area to Volume Ratio Flashcards
What is the relationship between the surface area and volume of an organism?
As the size of an organism increases: volume increases more than surface area increases
What is the environment around cells of multi cellular liquid?
Tissue fluid
What organisms require a larger volume to surface area ratio?
Organisms with a higher metabolic rate exchange more materials so require a larger surface area to volume ratio
How have large organisms evolved to speed up the rate of diffusion?
A flattened shape so no cell is far from the surface
Specialised exchange surfaces with large surface areas
What are the characteristics of specialised exchange surfaces?
Large surface area relative to volume
Very thin so diffusion distance is reduced
Selectively permeable to allow selected materials across
Movement of the environmental medium maintains the concentration gradient
A transport system to ensure the moment of the internal medium
How do you have to represent the surface area to volume ratio?
Surface Area : Volume as SA : 1