The Geological Time Scale Indicates the Order of Eras Is

question 6

Multiple Choice

The geological time scale indicates the order of eras is Cenozoic as the most recent; the middle era is the Mesozoic,with dinosaurs as the major group; and the earliest era is the Paleozoic.Consider a hillside of rock that surfaces in your backyard that is identified as dating back to the Mesozoic era.What is possible?

• A)Fossils from all other eras can still be found underneath if you dig far enough.
• B)All periods of fossils were once present in the backyard but older ones were eroded away.
• C)Fossils were mainly deposited when your backyard was sediment,so many layers might be missing,but any layer from Cenozoic to Paleozoic might be found.
• D)Fossils were mainly deposited when your backyard was sediment,so many layers might be missing,but any layer from earlier Mesozoic through Paleozoic might be found.
• E)Only one layer of fossils can be found at any site.

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Definitions:

Stereogenic Center

An atom in a molecule, often carbon, that is connected to four different groups, giving rise to stereoisomers due to the spatial arrangement of these groups.

Stereoisomer

Molecules that have the same molecular formula and sequence of bonded atoms but differ in the three-dimensional orientations of their atoms in space.

Drug Receptors

Specific molecular sites within the body that drugs interact with to produce a pharmacological effect.