Ventilation systems are needed in a <span>multicellular organism to actually obtain oxygen and give out carbon dioxide. Without this ventilation system, it would be very difficult for multicellular organisms to survive. It has been also observed that surface diffusion is not enough for a multicellular organism to breath.</span>
Taproot and Fibrous roots
Answer:
I think the answer would be D,I'm not really sure though,hope I'm right,sorry if I,m not :)
Explanation:
Because of the medication that people put in their head so that they can cure cancer
Fungi are classified based upon how they reproduce. The rest of the factors do not include anything of their classification.