Choose the correct answer from each of the four options given below:
Marine fish when placed in tap water bursts because of:
Topic: Endosmosis in a marine fish
Try it
Pick an option and check your answer. The full worked answer is below either way.
Answer
(a) Endosmosis.
A marine fish lives in SEA WATER, which is highly concentrated (hypertonic). Its body fluids are therefore LESS concentrated than the sea, and it is adapted to that.
Placed in TAP WATER — which is now HYPOTONIC relative to its body fluids — water rushes INTO the fish by ENDOSMOSIS. Its cells swell beyond what they can hold and burst.
THE PREFIXES decide the answer: ENDO- means INTO — water enters the cell EXO- means OUT of — water leaves the cell
Option (d) PLASMOLYSIS is the trap, but it is the consequence of water LEAVING a cell — the opposite of what happens here. And note that plasmolysis applies to PLANT cells, which have a wall; an animal cell with only a membrane BURSTS instead, which is exactly what the question describes.
Endosmosis.