Matching cell functions to organelle appearances

Steps:

• Function 1 (mRNA passes through to ribosome) matches nucleus: double membrane-bound, irregular structure (X).
• Function 2 (produce spindle during cell division) matches centrioles: non-membrane-bound, cylindrical structures arranged as flattened (Y).
• Function 3 (synthesis of polypeptides) matches ribosomes: non-membrane-bound, spherical structures (W).
• Option D assigns X to 1, Y to 2, W to 3, completing the correct matches.

Why D is correct:

• It aligns each function with the defining structure: nucleus (nuclear envelope for mRNA export), centrioles (microtubule organizers for spindle), ribosomes (protein synthesis sites).

Why the others are wrong:

• A: Assigns V (enclosed cavity, like vacuole) to function 1, not nucleus.
• B: Assigns Z (flattened sacs, like Golgi) to function 3, not ribosomes.
• C: Assigns V (enclosed cavity) to function 1, not nucleus.

Final answer: D