General Science question from Panchayat Secretary (VLW) exam, 2025 by JKSSB
Intact chloroplast from green leaves can be isolated by
Last updated Jun 9, 2026
Correct Answer:
Option D —
Sucrose solution
To isolate intact (undamaged) chloroplasts, scientists use an isotonic solution—meaning a solution that has the same solute concentration as the inside of the chloroplast.
Sucrose solution (usually around 0.3 to 0.4 M): Provides the perfect osmotic pressure. It prevents water from rushing into the chloroplast (which would make it burst) or rushing out (which would make it shrink).
Acetone and Alcohol: These are organic solvents. They would dissolve the lipid membranes of the chloroplast and destroy it completely.
NaCl solution: While sometimes used in rough extractions, a pure sodium chloride solution can cause ionic stress and is more likely to damage the delicate outer membranes compared to sucrose.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
