Cells support and nourish cells that send electrical signals throughout the body.

Correct Answer: B

Rationale: Neuroglia (e.g., astrocytes, oligodendrocytes) support and nourish neurons, which send electrical signals. Effectors respond, and receptors detect stimuli.

Correct Answer: D

Rationale: White matter’s white color comes from myelin, the lipid-rich sheath around axons, reflecting light. Dendrites and cell bodies are gray matter, and Nissl bodies are in cell bodies.

Correct Answer: B

Rationale: The nucleus resides in the cell body (soma), which integrates signals and maintains neuron function. Axons transmit, dendrites receive, and myelin sheaths insulate.

Correct Answer: C

Rationale: Unipolar neuron is a structural classification (one process). Interneuron, motor, and sensory are functional types.

Correct Answer: A

Rationale: Saltatory conduction is impulse jumping between nodes of Ranvier on myelinated axons, speeding transmission.