Cell Ultrastructure — Which two organelles most closely resemble each other in overall membrane architecture and cisternal/tubular organization?

Introduction:
This question probes recognition of organelle morphology. While many organelles are membrane-bound, their shapes and organizations differ: sheets, tubules, stacks, or vesicles. Identifying which pair appears most similar requires recalling the cisternal/tubular nature of the endomembrane system.

Given Data / Assumptions:

• Golgi apparatus consists of stacked, flattened cisternae with budding vesicles.
• Smooth ER forms an interconnected network of tubules and cisternae.
• Other options pair organelles with very different architectures.

Concept / Approach:
Focus on membrane topology and continuity. Golgi and smooth ER share sheet/tubule-like cisternal morphology and dynamic vesicular traffic within the endomembrane system, making them most alike visually and structurally at light/electron micrograph level.

Step-by-Step Solution:

Verification / Alternative check:
Both Golgi and smooth ER continuously exchange membranes and cargo, reinforcing their architectural similarity within the same trafficking system.

Why Other Options Are Wrong:

Common Pitfalls:
Equating 'membrane-bound' with 'structurally alike' without considering envelopes, stacks, and network geometry.

Final Answer:
Golgi apparatus and smooth ER.