Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland.In contrast to excretion, the substance may have a certain function, rather than being a waste product.ecretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland.
The oldest shark fossils. The oldest fossilized evidence of prehistoric sharks comes from shark-like scales that date to 455 million years ago during the Ordovician Period, in Colorado. Some paleontologists do not agree that these scales are sufficiently shark-like to pronounce them sharks.
Shark teeth are made up of calcium phosphate, which is the mineral apatite. Although shark teeth are sturdier than the cartilage that makes up their skeleton, the teeth still â¦ disintegrate over time unless they are fossilized.This is why you rarely find white shark teeth on a beach.hark teeth are made up of calcium phosphate, which is the mineral apatite. Although shark teeth are sturdier than the cartilage that makes up their skeleton, the teeth still â¦ disintegrate over time unless they are fossilized.