Water vs. Land

Part of Hall of Ocean Life.

Milstein Family Hall of Ocean Life Educator's Guide: Activity

What are the implications of life in water? Brainstorm with your students a list of things that are possible in water that are not possible on land, and vice versa. Record the students' responses on the board. Possible answers include types of locomotion (e.g., swimming or walking), feeding methods (e.g., filtration and chewing) and different kinds of communication (e.g., sonar or talking).

Activity extension:

Discuss with students that on land, living things are either supported internally by cell walls or possess an endo- or exoskeleton. In water, organisms that lack "organic support" such as a skeleton rely on the properties of buoyancy for external support. This activity will help students visualize how the properties of buoyancy affect the structure of an organism.

What you need:

  • Ziplock baggie
  • water
  • large clear container

What you do:

  1. Explain to students that the baggie represents certain kinds of marine life (such as jellyfish) that do not have exo- or endoskeletons.
  2. Fill a plastic Ziplock baggie with water and seal it closed.
  3. Place the "flimsy" water-filled baggie on a solid surface.
  4. Ask students to examine and describe the way it looks.
  5. Now, place the baggie in a clear, liquid-filled container. Ask students to notice the difference in the baggie's appearance in water, where it receives support from the surrounding water, as compared to out of the water, where there is less support.

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