Collin and Rob raced down to the ocean to go for a swim. The boys had just finished skateboarding and had worked up a sweat. They could hear the waves crashing onto shore and felt the cool ocean breeze. "That water sure does look nice," thought Collin, "and that breeze will make it feel even better." School had just gotten out and a long relaxing summer lay ahead. Along the path to the water the boys had to avoid many objects that were in their way. The sand seemed to be littered with everything. People were laying on towels next to coolers while beach umbrellas swayed in the ocean breeze. The way to the water became a game of dodging and weaving. They had to watch their every step. As they got closer to the shoreline the spray from the crashing waves fell on their faces. They quickly took off their sandals and staked out a spot for their stuff on the beach before they jumped in. As they were spreading out their towels Rob noticed something in the sand. "Collin, check this out." Rob dug into the sand and pulled out something that was full of holes. "This looks like what my mom uses to mop the floor... but it feels different!" Collin laugh, "Hey, you got yourself a new pet animal!" "What are you talking about?" asked Rob, "This is no animal." "Actually it is," replied Collin. "You are holding in your hand a live sea sponge. There are a lot of them around here in Tarpon Springs." Rob examined his new find. He smelled it and even tried to squeeze it. It looked just like a sponge... the kind his mom used on the dishes as well as the floor. He knew those sponges were not living or ever had been. How could this one be a living animal? Collin joked, "Take it easy man; you don't want to kill your new friend!" Rob asked, "Seriously, you are saying this is a living animal? I don't see any eyes, and it's not wiggling out of my hand. Prove it!" With that Collin smiled and said, "I'll prove it to you... after we prove this ocean can cool us off!"
How could Collin prove it?
1 answer
Collin could prove that the sea sponge is a living animal by taking it to the water and showing Rob how it reacts to being submerged. Sea sponges are filter feeders, meaning they extract nutrients from the water. Collin could place the sea sponge in the water and demonstrate how it expands and absorbs water, showing that it is a living organism capable of actively interacting with its environment.