Answer:
After an organism's soft tissues decay in sediment, the hard parts — particularly the bones — are left behind. Water seeps into the remains, and minerals dissolved in the water seep into the spaces within the remains, where they form crystals. ... If that mold gets filled with other minerals, it becomes a cast.
Explanation:
The main reason for the species extinction is for the ecological changes.
<span>Chlorofluorocarbons
(CFCs) chemicals contain carbon, chlorine and fluorine and is t so expensive at
the same time it’s not flammable, the reason why it is mainly used in business
such as refrigerators and plastics. However, these chemicals destroys our
stratosphere, the second layer of the Earth’s atmosphere and protects us by
blocking the ultraviolet radiation (UV Light). This type of radiation can seep
through organisms skins and can leave destructive effects on DNA molecules
which will also cause skin cancer.</span>
The first step the biologist needs to make an observation in which to create a hypothesis.
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