Before activity begins
plant rice seeds in seedling trays until you have six seedlings of roughly
equal size (can do this with students).
Explain to students that
they will be determining what plants need to survive. Set six flower pots
up in the classroom near a sunny window. Fill four with potting soil. Another
one will have potting soil with grass growing in it. This can be accomplished
either by planting grass seed in the pot a few weeks before the activity begins,
or by buying a square of grass turf at a nursery and cutting it out to fit
the pot. The last one will have not have soil in it. Each pot will be labeled.
The pot with no soil will be labeled "No soil". The pot with grass
will be labeled "No space". The other four will be labeled "No
air", "No water", "No sunlight" and "Control".
Each pot will have a seedling placed in it. The ones with soil will have the
seedlings transplanted into the soil.. The empty pot will have the seedling
placed on the bottom of it. Except for the pot labeled "No water",
all of the pots will be watered. After watering, the "No air" pot
will be placed in a sealed Spacebag with the air removed and the "No
light" pot will be placed under an aerated opaque cover.
Each day the students
will water the pots, except the "No water" pot, and observe what
is happening in each of them. They will write or draw their observations in
a journal. If the students are not able to write yet, the teacher should record
the students’ observations in a classroom journal or have students draw their
observations in their own journals. They should do this each day with the
day labeled. If they see no change, they should write "No change".
For example:
Day 3 No soil: No change No space: No change No air: No change No sunlight: No change No water: Turning brown, leaves wilting Control: Growing
After two weeks, the
students should compare what happened to each of the rice seedlings.
The students will review their journals, compare the things each plant was
receiving or not receiving, what happened to each plant because of this and
make guesses about what plants need to survive. Class will discuss the results
and consider whether they think their results are true of all plants.