20% of the Earths crust is made up of non-silicate minerals
The deep sea vent organisms or benthic organisms normally live in dark conditions because of no penetration of sunlight. These organisms in order to colonize ocean surface must develop photo sensory receptors and should adapt to the light conditions along with variation in temperatures and pressure in ocean currents.
<span>They are cellular parasites.
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The answer is C. Because they do have scales