NN-20: Sometimes Litter is Rotten
Materials List:
NOTE: ALLOW AT LEAST 7 TO 10 DAYS FOR FOOD TO DEVELOP A GOOD MOLD CULTURE (bread that
contains additives to prevent spoilage, takes a week or more to show mold)
-Clear plastic containers (in learning station) for moldy items
-Various kinds of moldy food items 9 dig into the back of your fridge
a. bread
b. boiled potato,
c. fruit
-Branch with signs of insect activity, and/or lichen
-Fungi (different types)
-edible mushroom (get a large old one from the supermarket if you wish)
-Invertebrate decomposers (no sow/pillbugs if Sam & Pat are being done)
a. earthworm
b. slug
c. snail
d. bark or ground beetles
-Samples of non biodegradable items
a. glass
b. tin or aluminum can
-Hand lenses (one for each student in group)
-"Lots of Rot" photo copies to show types of molds (one copy for each student in group)
-Decomposing soil sample
-Paper Towels
-Paper Plates
Nature In Your Neighborhood
Some Times Litter Is Rotten
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SOME TIMES LITTER IS ROTTEN
Source:
NN – 20
July 1994
Joan Coston
Objective:
To increase students' awareness about different deomposers, why decomposition is
essential and what is recycling.
Science Themes:
Patterns of change, systems and interaction, energy
Process Skills:
Observing, comparing, relating, applying
Grade Level:
3rd
Focus Words: Decomposer, litter, non–biodegradable, biodegradable, nutrient, recycle,
reduce, reuse, fungi, bacteria, molds
Background Information:
If dead things didn't decompose we would be up to our ears in dead plants and animals.
Decomposers, after they have taken in their necessary food, recycle dead plants and animals by
returning important nutrients to the soil which makes it possible for new plants to grow.
Activity:
ALLOW 7 to 10 DAYS FOR FOOD TO DEVELOP A GOOD MOLD CULTURE
You may already know some kinds of decomposers: mushrooms, snails and insects. Other kinds of
decomposers, bacteria and mold spores, float in the air all around us all the time but are so small you
cant see them. You don't know about them unless you give then a place to live. For example, on this
piece of bread and potato (or what ever you brought with you to show the students) they have grown
and we can see them.
We can see them even better with a hand magnifying glass. Can you see the white fuzzy spots that
look like roots and branches and have black on them? The black bits are the reproductive (makes
new mold plants) parts of the mold. This part makes the spores that float in the air and, when they
land on the right kind of surface, produce new mold plants.
The white fuzzy spots have long root-like extensions that are taking nutrients from the bread and this
helps break down the bread, decomposes it. This is called black bread mold.
Besides mold you may discover shiny round white bumps on the potato. These are colonies of
growing bacteria.
Things that are easy for us to digest, like bread or potato, will easily grow molds and bacteria in just
a few days. However, other things like a tree branch, may need other decomposers or scavengers to
help decompose the plant tissues. After the tissue has been broken down by these other organisms,
then molds and bacteria can continue the job.
Look at the tree branch. What kinds of decomposers have been at work here?
Nature In Your Neighborhood
Some Times Litter Is Rotten
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Insects? Worms? Lichen? Fungi? If you have a store mushroom with fully open cap pass it around
here so everyone can find the gills, cap, stem and spores.
Have each student look closely (use magnifiers) at a different kind of decomposer, i.e. earthworm,
snail, insect, mold, fungus and describe it to the rest of the group. Discus how each does its job of
decomposing.
After everyone has had time to inspect the various items and there has been time to answer their
questions as well as ask them specifics about what they have discovered, then explain the concept of
biodegradable. Discuss the similarity of the terms decompose, rot and biodegrade. Ask them if they
know what organic means. Ask the students if they can think of any other words that are similar to
these.
Ask students if they can think of words that might be the opposite of biodegradable, photodegradable
or decompose (non biodegradable, or grow). What things can the students name that are not
biodegradable.
Introduce the term RECYCLE.
Ask the students for an example and help out so they know what recycle means.
Pass out the non biodegradable items, be sure each student gets one, and ask how the students would
best use them. They should tell you if they think their item can be recycled. Ask them if they
understand what the saying, "there is no away" means. Ask what recycle means to them.
If time permits, some other terms you may wish to discuss while passing around some of the non
biodegradable items are:
Soluble
Compost
Landfill
Durable
Petroleum by-product
Non-renewable resource
Source reduction
Non-point source pollution
Nature In Your Neighborhood
Some Times Litter Is Rotten
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