Living, Non-living vs. Dead Lab

Part 1 (Living-Nonliving Part 2)

I have found that it is worth spending two full class periods on a lab that challenges students' preconceptions of what it means to be alive! I designed this lab years ago, and it remains a favorite of mine. A free student handout is available at the end of this article.

The day before lab day (may only need a 1/2 class period) we brainstorm qualities that living things must have. At this point I just let students list a bunch of things on the board, and I don't filter them at all. Then as ideas slow down, we start lumping overlapping ideas together. From our list, each student chooses 10 to list on their data table. Below is a list of common characteristics student usually come up with. Remember, its OK if they come up with characteristics that are not the  actual characteristics of life. By completing the lab, they'll figure out that some of the characteristics they choose are not good indicators of life! And some that might be the best indicators are not always easy to observe!

• need air
• breaths
• poops
• exhales
• moves
• reacts to stimuli/environment
• needs food/eats
• needs water/drinks
• has cells 
• has atoms
• it can die (I love this one)
• thinks
• has babies/offspring
• has genetic material
• has chemical reactions going on inside of it

The next day, the students rotate around to 12-15 stations. Student's goal is to determine which characteristics they have in their chart apply to the entity they are observing. Then, they must make a final decisions as to whether or not the item is living, non-living, or dead. This is what the table looks like.

When deciding what to put at each of the stations, I like to choose some that are easily identifiable as living & dead, and others that are more difficult and will provide a wonderful opportunity to discuss. Here is a list of items I have used in the past. Living = L, Non-Living = NV, Dead = D.

• rock (NV)
• potted plant (L)
• freshly cut flower in water (L, we have fun with this and the next one)
• freshly cut flower not in water (L...but dying?)
• yeast in warm water and in water bath (L)
• oil in water with green food coloring, and in a warm water bath (NL)
• candle flame (NL--another fun one to discuss)
• sewer lice (NL)
• microscope station set up slide of an elodea leaf (L)
• microscope station set up with a slide of a wet mount of just water and focus on an air bubble! Looks like an amoeba  (NL)
• microscope station set up with a slide of yogurt (L)
• mold growing on food (L)
• goldfish swimming (L)
• cork (D)
• apple (L)
• package of seeds (L, Usually students say D, but during discussion, we are able determine that although it has no characteristics of life, now, it has the potential to, and therefore is living...usually a student comes up with the word hibernate to describe seeds.)
• germinating seed (L, good to use in comparison to the seeds in a package)
• Sewer Lice or Dancing Raisins- raisins bobbing in clear soda pop (NL-D?)
• Glue Monsters- wood chips being eaten by Duco cement (NL-D?) (I have posted videos of this in part 2 of this post!) 

Students then must finish the post lab questions for homework. In these questions, students must synthesize which characteristics are the best indicators of life, they share what areas they are most certain, and others where they feel they don't have enough information. Questions also challenge them to really look at how their observations measure up to their "gut feelings" about some of the items. Its common for students to know that the candle flame is non-living, and yet it has more check marks of characteristics of living things, then some of the items they know to be living. I have them think about what this may mean, and what it may indicate about how hard it is to classify items as living or non-living!

My favorite question is one where they must pick an item they characterized as non-living, and for fun, argue that it is living. Many students choose candle flame, since it has many of the characteristics.  The last page of the lab has a list of other items that they must put through their vetting system and characterize. Some of these include, whale sperm, HIV virus, chicken egg bought in a grocery story, and fertilized egg. I tell them I won't be grading their lab for the "book answers," instead, I want them to really THINK, and as long as they can verbally,and in their written answers defend why they've classified a certain item, they can receive full credit! As you can imagine, students come in the next day excited to defend their position on some of these items. We really enjoy the day after lab as it provides that opportunity for rich discussion. Some years I tell them what was at each station, and other years I don't. During these discussions I encourage peer-peer interaction, only interjecting questions  like "So, what happens if I put water on the flame?" 

I originally designed the Living, Non-Living lab as a way to introduce the characteristics of life. I figured it was better for them to begin our biology class understanding that its is not as easy  as they may think to define life.  But I soon discovered that the students learned several other important scientific skills as a result of this lab. Because it is the first lab of the school year in my biology class, it is a perfect lab to help me introduce my students to lab stations, lab safety, and the behavior I expect in the lab. Therefore, the best aspect of this lab is the discussions it encourages the student to have. It helps me to foster that environment of taking guesses, helping student to not worry about being wrong, but making predictions based on what they already know.  

The free printable is the student handout which is 4 pages long. The first page includes the brainstorming questions you might cover in your discussion the day before the activity. The data table where they record their observations is on the last page, and the other pages include postlab questions, based on a wonderful discussion we had on the NSTA listserves! I would LOVE feedback if you decide to use this lab!

Living-Nonliving Part 2: I've written another post on how to make stations "tricky." It includes a tutorial of how to do the "Glue Monsters" demo, and I include a video, if you can't spare the time to do the demo yourself!

I'd love to hear what you've done to help teach these important ideas and skills!