topic 02 - gas exchange

• what is the SA to volume ratio like when an organism is small? meaning?

  when an organisms' size/volume is small the SA to volume ratio is large meaning the organisms can survive by exchanging materials by diffusion.
• how do single celled organisms exchange gas?

  through diffusion.
• how large are single celled organisms?

  they are micrometers or nanometers.
• what do single celled organisms do as they respire?

  they take in oxygen and remove carbon dioxide as they respire.