The osmotic expansion of a cell kept in water is chiefly regulated by: [2014]a)Mitochondriab)Vacuolesc)Plastidsd)RibosomesCorrect answer is option 'B'. Can you explain this answer?

Question

The osmotic expansion of a cell kept in water is chiefly regulated by:     [2014]a)Mitochondriab)Vacuolesc)Plastidsd)RibosomesCorrect answer is option 'B'. Can you explain this answer?

Answer

Vacuoles are non cytoplasmic areas present inside cytoplasm and separated from latter by tonoplast. They are believed to be formed by expansion and pinching off from ER. There occurs a large central vacuole and many small vacuoles in plant cells. They play a major role in osmotic expansion of cell.

Answer

Answer

Understanding Osmotic Expansion in Cells
Osmotic expansion occurs when a cell is placed in a hypotonic solution, such as water, which leads to water entering the cell. This process is crucial for maintaining cellular integrity and function.
Role of the Vacuole
- The vacuole is a membrane-bound organelle found in plant cells that plays a significant role in regulating osmotic pressure.
- It stores water, ions, and nutrients, contributing to the turgor pressure necessary for cell stability.
- When a plant cell is immersed in water, the vacuole absorbs excess water, leading to expansion without bursting, due to the rigid cell wall that provides structural support.
Osmoregulation
- The vacuole aids in osmoregulation—the process by which cells maintain fluid balance and concentration of solutes.
- By controlling the influx and efflux of water and solutes, the vacuole helps prevent excessive swelling and potential damage to the cell.
Comparative Roles of Other Organelles
- Mitochondria primarily manage energy production through respiration, not osmotic regulation.
- Plastids are involved in photosynthesis and storage but do not directly influence osmotic pressure.
- Ribosomes are responsible for protein synthesis and have no role in regulating osmotic expansion.
Conclusion
In summary, the vacuole is the organelle chiefly responsible for regulating osmotic expansion in cells kept in water, ensuring that the cell maintains its shape and function without bursting. Understanding this process is essential for grasping how cells interact with their environments, particularly in plant biology.

Top Courses for NEETView all

Daily Test for NEET Preparation

NEET Mock Test Series - Updated 2026 Pattern

Topic-wise MCQ Tests for NEET

Biology Class 11

DPP: Daily Practice Problems for NEET

Top Courses for NEET

Top Courses for NEET

Related Content

Mock Test & Practice

Main Subjects

Guided Learning

Revision

Competitive & Government Exams