AS CAN BE SEEN BY THE FOLLOWING ARTICLE OTHER THINGS THAN IRON CAN BE AND ARE USED AS A TRANSPORTER OF OXYGEN, SO WHY NOT A SUBSTITUTE FOR CARBON?Octopuses are characterized by their eight arms (not tentacles), usually bearing suction cups. These arms are a type of muscular hydrostat. Unlike most other cephalopods, the majority of octopuses — those in the suborder most commonly known, Incirrina — have almost entirely soft bodies with no internal skeleton. They have neither a protective outer shell like the nautilus, nor any vestige of an internal shell or bones, like cuttlefish or squids. A beak, similar in shape to a parrot's beak, is the only hard part of their body. This enables them to squeeze through very narrow slits between underwater rocks, which is very helpful when they are fleeing from morays or other predatory fish. The octopuses in the less familiar Cirrina suborder have two fins and an internal shell, generally lessening their ability to squeeze into small spaces.
Octopuses have a relatively short life span, and some species live for as little as six months. Larger species, such as the North Pacific Giant Octopus, may live for up to five years under suitable circumstances. However, reproduction is a cause of death: males can only live for a few months after mating, and females die shortly after their eggs hatch. They neglect to eat during the (roughly) one month period spent taking care of their unhatched eggs, but they don't die of starvation. Endocrine secretions from the two optic glands are the cause of genetically-programmed death (and if these glands are surgically removed, the octopus may live many months beyond reproduction, until she finally starves).
Octopuses have three hearts. Two pump blood through each of the two gills, while the third pumps blood through the body. Octopus blood contains the copper-rich protein hemocyanin for transporting oxygen. Although less efficient under normal conditions than the iron-rich hemoglobin of vertebrates, in cold conditions with low oxygen pressure, hemoglobin oxygen transportation is less efficient than hemocyanin oxygen transportation. The hemocyanin is dissolved in the plasma instead of being bound in red blood cells and gives the blood a blue color. Octopuses draw water into their mantle cavity where it passes through its gills. As mollusks, octopuses have gills that are finely divided and vascularized outgrowths of either the outer or the inner body surface.
[edit] Intelligence
2007-10-26 04:58:49
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answer #1
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answered by Loren S 7
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Unlikely. Years ago there were suggestions that silicon could act as a basis for life instead of carbon, but chemically it doesn't even come close to carbon in the variety of chemical structures that can be formed. I'm saying this badly, but its been far too long since my last organic chemistry course to remember the details.
Carbon is a common element in the universe. There isn't any good reason that a planet would be deficient in that element. And when both are present, carbon would always be the best choice for life.
2007-10-26 04:50:02
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answer #2
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answered by Anonymous
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No - in fact if you know how life originated in this universe, then you won't ask this. Life on any other planet can only be carbon based and nothing esle.
2007-10-26 06:01:16
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answer #3
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answered by Anonymous
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