Question

Some inquisitive students found two slugs and wanted to take them to science class. The only container they could find was a used potato chip bag. The students stored the slugs in the bag to take to school the next day, When the students opened the bag at school, they found that the slugs had melted and turned to slime. Explain why this happen? A) The slugs had an defensive reaction to the salt, and the slime was a response to that reaction. B) The salt around the slugs created a hypotonic environment, which caused water to diffuse into cells and made them undergo cytolysis. C) The salt around the slugs created a hypertonic environment, which caused water to diffuse out of cells and the cells will shrink. D) The salt around the slugs created an isotonic environment, which caused water to diffuse out of and into the cells which made the slugs melt.

Answer 1

The correct answer is: C).

Explanation:

• Slugs are organisms which belong to the Phylum Mollusc.
• Their specific morphological feature is that they lack a proper shell structure.
• Their bodies store a huge amount of water and they also produce mucus called slime which help them protect against desiccation and predators.
• In the given question, the slugs are kept in a chips packet.
• The chips packet is lined with particles of salt.
• The concentration of salt inside the chips packet, that is, outside the body of the slug is more than the concentration of salt inside the body of the slug. This makes the chips packet a hypertonic environment as compared the interior of the body of the slug.
• Also, the concentration of water is higher inside the body of the slug as compared to that inside the chips packet. This makes the interior of slug body hypotonic as compared to chips packet.
• Osmosis is the process by which molecules move from a region where their  concentration is high to a region where their concentration is low across a selectively-permeable membrane.
• Also, Osmosis can be defined as the process by which water tend to move from a region where the concentration of solute (salt) is low (inside the slug body) to the region where the concentration of solute (salt) is high (in the chips packet) across a selectively permeable membrane (the external lining of the slug body).
• Hence, the slug releases the water present in its body in the form of mucus, which is the slime, and shrinks in size when kept in a hypertonic environment.