Question

Classify the following into osmosis/diffusion.
Earthworm dying on coming in contact with common salt.

Answer 1

Osmosis is the spontaneous net movement of solvent molecules through a semi permeable membrane into a region of higher solute concentration in the direction that tends to equalize the solute concentration on the two sides. The earthworm is dehydrated as its integumentary system uses diffusion/osmosis to remove carbon dioxide and take oxygen. They cannot tolerate high salt stress as they do not have control over the osmotic regulation. The salt stress and desiccation significantly interfere with the functions of neurosecretory cells. Hence, salt is extremely toxic for earthworms.