Question

When placed in tap water, marine fish die because of ______.

Options

• endosmosis

• exosmosis

• diffusion

• plasmolysis

Answer 1

When placed in tap water, marine fish die because of endosmosis.

Explanation:

The bodily fluids of a marine fish are hypertonic (highly concentrated with salts) compared to fresh tap water, which is hypotonic. When the fish is placed in tap water, water naturally rushes into its cells via endosmosis down the water potential gradient. This rapid and uncontrollable influx of water causes the fish’s cells and tissues to swell and rupture, quickly leading to organ failure and death.