The answer is 3. <span>made from the remains of living organisms.
Sedimentary rocks are formed at Earth's surface. They can be clastic, chemical, and organic.
Clastic sedimentary rocks are the result of sedimentation of rocks and mineral fragments. Chemical sedimentary rocks are the result of sedimentation of chemical solutions of dissolved minerals.
<em>Organic sedimentary rocks are made from the remains of living organisms, fossils and corals.</em>
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<span>They are not visible because the chromatin coils up,shortens,and thickens.</span>
Natural selection means that the organisms better adapted to their environment, that is, they have developed the right characteristics/skills/response to the external ambient, have higher chance to survive, making the next generations genetically inherit such acquired surviving characteristics.
These generations will thus have a higher chance of survival, making these species being "naturally selected" as survivors, while those who haven't or are slower in this process, have a higher risk of elimination.
