Can help prevent heart attacks
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>
The first piece of evidence that needed to be found to support the endosymbiotic hypothesis was whether or not mitochondria and chloroplasts have their own DNA and if this DNA is similar to bacterial DNA. This was later proven to be true for DNA, RNA, ribosomes, chlorophyll (for chloroplasts), and protein synthesis.
<span>Explanation: Oxygen is the more electro-negative of the atoms in the water molecule, so it tends to pull the 'shared' electron more to itself. Thus, the oxygen atom has a greater time-share of all electrons, and therefore the hydrogen atoms are more positive for a partial lack of electrons</span>
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A. this is because if it is warmer, their ice will melt and they will have less ice for them to live on.
