What is life?

What is Life?

Rachel Sanders, Biology, Rivendell Academy

Imagine a cut flower in a jar water. What do you notice about this flower? Is it alive? What if the flower is removed from the water? If the flower is alive, how will I know when it dies? In this critical exploration, I begin by asking students to use evidence and reasoning to explore the “aliveness” of the flower, with the ultimate goal of considering how scientists might determine if something is alive. They dissect the flower and examine it under a microscope. They then observe other organisms and parts of organisms like skulls and mushrooms with the same questions in mind. Over the next few weeks, students continue with experimentation and discussion to develop a set of “rules” for knowing if something is alive.

Teacher Reflection

I am always surprised by the variety of responses to this puzzle of life. Students claim that the flower dies immediately after being cut, but others claim that it is alive because it contains seeds that can grow new life. They devise experiments to test for life and pull in knowledge from previous classes to share and evaluate. Many express surprise that what seemed like a simple question on the surface is filled with uncertainty.

Student Reflections

“On a molecular level, we are a lot like dead things that can move.”

“One thing another student said that surprised me was that the mushroom was dependent on something dead and the skull was dependent on something alive. It surprised me because I never knew this or thought about an object being dependent on something that was / is alive or dead.”

“The comments caused me to wonder if parts of something like organs or organ systems could be alive.”