2011 â The first of its kind in North America, EdgeWalk is the worldâs highest full circle hands-free walk on a 5 ft (1.5 m) wide ledge encircling the top of the CN Towerâs main pod, 356m, (1168 ft, 116 stories) above the ground.
Why does cellular respiration add carbon dioxide to the atmosphere but photosynthesis does not? During photosynthesis, carbon dioxide and water are used to produce sugars and oxygen. During respiration, the sugar glucose and oxygen and used to produce carbon dioxide and â¦water.  Resource: Science Explorer. Prentice Hall Life Science Text Book. No copyright intended.
In many bivalves and snails, and in cephalopods, part of the mantle is modified into a siphon, which can be used to pump water through the mantle cavity for respiration, feeding and/or jet propulsion. Freshwater and marine mollusks have gills (called ctenidia) for respiration, located in the mantle cavity. In most bivalves, these are enlarged and serve to trap food particles as well (Morton 1983).