Question

A marine clam is mistakenly added to a freshwater aquarium. What will happen to the clam and why? Popcorn sold at movie theaters is very salty, causing people to become thirsty and to buy so drinks. Explain why salty popcorn causes this thirst.

Answer 1

Answer:

The clam would die. This is because its cells would swell up and lyse. The freshwater is hypotonic to the cell’s protoplasm. Water, therefore, enters the cells through osmosis and the cell swell up until the water pressure inside causes them to burst. The cells die and therefore the clam is unable to survive in the freshwater.

The salt in the popcorn is taken up by the body and hence the concentration of electrolytes in the blood slightly increases. This causes a feedback mechanism to be  initiated by the body –hypothalamus in particular-  to restore electrolyte homeostasis. The thirst is as a result of an increase in antidiuretic hormone in the body produced by the pituitary gland.