In plant cells, which organelle often stores water and helps maintain turgor pressure?

• A. Vacuole
• B. Mitochondria
• C. Nucleus
• D. Chloroplast

Answer: (A)

In plant cells, maintaining rigidity and shape relies on turgor pressure, which comes from water stored in the large central vacuole. This vacuole holds water and dissolved substances, and its membrane (tonoplast) regulates water movement. When the vacuole is full, it pushes against the cell wall, creating turgor pressure that keeps the plant cells firm and helps the plant stay upright. If water is lost, the vacuole shrinks, turgor drops, and cells wilt. Other organelles have different roles: mitochondria produce energy (ATP), the nucleus stores genetic material, and chloroplasts carry out photosynthesis. The vacuole is the organelle most closely associated with storing water and sustaining turgor.