The Danish Physician Who Developed the Geologic Principle of Superposition

question 5

Multiple Choice

The Danish physician who developed the geologic principle of superposition, according to which rocks (and fossils) higher in a sequence are younger than those buried farther down, was

• A)Charles Lyell.
• B)Niels Stensen (aka Nicolaus Steno).
• C)William Smith.
• D)James Hutton.

---

Definitions:

Depolarization

A reduction in the difference in electric charge across a cell membrane, which is essential for generating action potentials in neurons and muscle cells.

Repolarization

The process of restoring the negative charge inside the cell membrane after a depolarization event.

Afterpotential

The change in membrane potential that follows the completion of an action potential in nerve cells.

Astrocytes

Star-shaped glial cells in the brain and spinal cord, involved in physical and nutritional support for neurons, and the repair and scarring process following central nervous system injury.