What is the organ that serves as the starting point of the respiratory system?

The organ that serves as the starting point of the respiratory system would be the nose.  It is where respiration starts by taking in the air from the atmosphere and it also ends here by breathing out carbon dioxide a waste gas produced from the processes in the body which is not utilized by our body.

The type of bond found in many carbon-to-carbon bonds in canola oil but very few carbon-to-carbon bonds in butter, is ; c=cc-c c=c c=h c-h hope this .