Biological Levels of Organization

Steps:

• Recall hierarchy: cell (basic unit), tissue (group of cells), organ (structure of tissues), organ system (organs working together).
• Examine each option's four terms in sequence for matching this order.
• Eliminate options where any term fails to fit the level.
• Identify the option with one correct example per level.

Why D is correct:

• Neurone is a specialized cell, muscle is a contractile tissue, leaf is a photosynthetic organ, and urinary is the excretory organ system, aligning with the definitional hierarchy of biological organization.

Why the others are wrong:

• A: Chloroplast is an organelle, not a cell.
• B: Sap vacuole is an organelle, not a tissue.
• C: Sap vacuole is an organelle, not a tissue.

Final answer: D