question_answer 64)

When a freshly collected Spirogyra filament is kept in a 10% potassium nitrate solution, it is observed that the protoplasm shrinks in size (a) What is this phenomenon called? (b) What will happen if the filament is replaced in distilled water?

Answer:

                  (a) Plasmolysis is the name of the phenomenon, occurring is Spirogyra filament whenplaced in 10% potassium nitrate solution (hypertonic solution). It occurs as water fromthe cell is drown out to extracellular fluid causing the protoplast to shrink away from cellwall. (b) When the Spirogyra again reabsorb water, protoplast will again and will come back in itsoriginal shape. This phenomenon is known as deplasmolysis.