A Simple Biosphere

"Since plants produce their own food, they need not get it from an outside source. Under the right conditions, then, plants are self sustaining."

Take a two liter bottle and cut the bottom off about 1/4-1/3 from the bottom. Fill the bottom part with soil. Plant seeds or replant seedlings or a plant in the soil. Moisten the soil well, but do not soak it. Take clear packing tape to reseal the top part to the bottom part. A self-contained biosphere.

Mark the height of the plant on the side of the bottle, and check it every few days and see how much and how quickly your plant grows.

sources: 

• Exploring Creation with General Science, Jay Wile
• GEMS Guide, Terrarium Habitats 
Kindergarten-6th grade
5 Activities
92 pages
These activities bring the natural world into your classroom and deepen student understanding of and connection to all living things. After an exploration of soil, students design and construct terrariums. Sow bugs, earthworms, and crickets are placed in the habitat, and students observe and record changes over time. There are detailed instructions on setting up and maintaining the terrariums, along with concise biological information on small organisms that can become terrarium inhabitants.