Orion Is Visible on Winter Evenings in the Northern Hemisphere

question 113

Multiple Choice

Orion is visible on winter evenings in the northern hemisphere but not summer evenings because of

• A)interference from the full Moon.
• B)the tilt of Earth's axis.
• C)the location of Earth in its orbit.
• D)the precession of Earth's axis.
• E)baseball on television.

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Definitions:

Oligodendroglia

Glial cells in the CNS that myelinate axons.

Myelin

A fatty substance that surrounds the axon of some nerve cells, forming an insulating layer that is essential for the proper functioning of the nervous system, speeding up the transmission of nerve impulses.

Saltatory Conduction

A process whereby nerve impulses jump between gaps in the myelin sheath of neurons, speeding up signal transmission.

Nodes

Points of intersection or branching in a network or circuit, often used in the context of biological and technological systems.