Using your knowledge of surface area and its effect on diffusion, explain why most multicellular organisms need respiratory and circulatory systems.
Answers
Answer:
All organisms need to respire. Unicellelluar organisms have enough contact with their surroundings to complete the action of respiration through diffusion. But in the case of multicellular bodies, All the cells may not have enough contact with the surroundings hence diffusion wont be enough for it. Thats why they need complex respiratory organs/organ systems to do this life process
Long Explanation:
In the case of a single-celled organism, no specific organs for taking
in food, exchange of gases or removal of wastes may be needed because
the entire surface of the organism is in contact with the environment.
These waste byproducts are therefore needed to be removed from the body and discarded
outside by a process called excretion. Again, if the basic rules for bodydesign in multi-cellular organisms are followed, a specialised tissue for
excretion will be developed, which means that the transportation system
will need to transport waste away from cells to this excretory tissue.