Question

Chloroplasts are isolated from green leaves using sugar solution because

• A. They are osmotically strong and burst in water.
• B. They are osmotically fragile and burst in water.
• C. They are soluble in water.
• D. None of the above.

Answer 1

The correct option is B They are osmotically fragile and burst in water.

Unlike isolated plant cells, isolated cell organelles like chloroplasts and mitochondria cannot be kept in distilled water as they would burst. The whole plant cells are surrounded by a cellulosic cell wall while the organelles are surrounded by the only membrane. When cell organelles are kept in distilled water, they gain water due to endosmosis and if the process continues they may burst. Hence, the cell organelles are isolated in a sugar solution to avoid any osmotic shock to the fragile and delicate cell organelles. Thus, the correct answer is option B.