Thinking about trees is a good way to wrap your brain around how different producers really are.

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Home - The Food Web - Producers

Link to Producers

Link to Secondary Consumers

Following the Producers video, take the next step up the food chain, and learn about herbivores.

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I really like plums. Several days ago I picked up several from the grocery, but when I tasted one, it was hard and too sour. Like most fruit, plums are picked before they are ripe, so they will make it to the grocery without getting mashed. What I needed was a way to get the plums to ripen quickly. Luckily, with a little science, it is easy. You can try this too. You will need:

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Use chemistry to change the colors in a bouquet of flowers.

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How do plants move water and food without a heart for a pump?

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Link to Primary Consumers

Link to Secondary Consumers

Explore the role of producers, organisms that specialize in capturing energy, converting it into useable forms, and storing it.

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This week's experiment is the result of a marvelous trip we took yesterday to the Okefenokee National Wildlife Refuge.  Nancy spotted an amazing number of wildflowers, which I photographed, and am now trying to identify.   Luckily, the flowering plants can be divided into two groups, the Monocotyledons and the Dicotyledons, often known as Monocots and Dicots.  To learn about sorting plants into these two groups, you will need:

- leaves and flowers from different kinds of plants

First, lets take a look at those long, complex names.  What in the world does Monocotyledon mean?  Or Dicotyledon?  Notice that they both have the same ending.  A cotlyedon is also known as  seed-leaf.  This is the first leaf that emerges from the seed.  Next, take a look at the first part of each word.  Mono- means one, and Di- means two.  Once you know that, then the difference between the two groups is easy.  Monocots have a single leaf when the seed sprouts, while Dicots have two.  

Knowing that, it is easy to tell the difference between the two, if you grow them from seeds.  If you have ever planted a garden, then you can probably recognize plants from both groups.  Corn, onions, and garlic have a single leaf when they sprout, which makes them monocots.  Squash, beans, cucumbers, and most other garden vegetables have two leaves when they sprout, so they are dicots.

That is great if you have the time to gather seeds from your wildflowers, and then wait for them to sprout.  (Do NOT collect seeds or anything else in National Parks or Wildlife Refuges!)  Luckily, there are other ways to separate the two groups.

One "test" that usually works is to look at the veins in their leaves.  Most monocots have veins that are parallel, running side by side.  To see an example of this, look at a blade of grass.  Most dicots have leaves with veins that form networks.  Look at the leaf of lettuce, or a leaf from an oak or maple tree.  Notice that I said "most" for both.  This is not an absolute test, but it will usually put you on the right path.

Another test involves cutting the plant's stem.  (Do NOT chop up plants or anything else in National Parks or Wildlife Refuges!)  Use a sharp knife to cut through the stem, and then examine it with a magnifying glass or microscope.  You are looking for the vascular bundles that carry food and water through the plant.  For dicots, the vascular bundles are arranged in rings or lines.  For an easy example of that, chop some celery. The "strings" in the celery are the vascular bundles, and you will find them lined up in a nice row.  That tells us that celery is a dicot.  For monocots, the vascular bundles are spread through the entire stem.  While you are chopping your celery, chop some hearts of palm or some bamboo shoots.  Neither will have that distinctive row of vascular tubes, since palms and bamboo are both monocots.  Mix both of these with the dicot lettuce leaves, and you are well on your way towards a delicious salad.  As you add other yummies to your salad (cucumbers, tomatoes, onions, carrots. etc.), try to determine which are monocots and which are dicots.

For my purposes, the best test was to look at the plant's flowers.  Since the flowers are what we were photographing, this is just what I wanted.  All you have to do is count the number of petals, sepals, stamens, and pistils.  

For monocots, these will be in multiples of three.  If you count the number of petals on the flower, it would have either three, six, nine, or a multiple of three.  The same is true for the stamens (the part that produces the pollen), and the sepals (the leaves around the base of the flower.  Be warned that this can sometimes be difficult to see. 

For dicots, the parts will be in multiples of four or five, so a dicot flower might have four petals, five petals, eight, ten, etc.  Again, be warned that plants can be tricky.  Some plants may have one or more tiny petals that are hard to find.  

OK, so now you are ready to test your new knowledge.  You could head for your local swamp, but there is a much easier field trip that you can make.  Head for your local grocery store.  Look through the produce section, and you should find a wide variety of both monocots and dicots.  Most groceries also have a section for live flowers, which will give you a great chance to count some petals.  Your local garden shop will also have quite a few examples from each group.  Even simpler, go out in your yard.  A close look at your lawn should give you plenty of plants to work with, although most of them will not be as tasty as what you would find at the grocery.

Have a wonder-filled week.

You don't have to go on safari to see some amazing wild life.

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How do plants spread their seeds to new areas?

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This week's experiment comes from tonight's supper. I have been craving a big pot of Great Northern Beans; so last night I put some into a pot of water to soak overnight. The results reminded me of a fun science experiment. To try it, you will need:

- a package of dry beans (any kind will do)
- a drinking glass
- water
-a metal cookie sheet or cake pan

Fill the glass full of dry beans. Add enough water to fill it to the top, and place the glass in the center of the metal pan. Put it somewhere nearby, where it won't be in the way, and then go about your daily routine. After a few hours, you will hear a clink as one of the beans falls out of the glass onto the pan. Then you will hear another. Over the next few hours, you will continue to hear the sounds of the beans falling, so unless you are a heavy sleeper, don't try this at night. (And of course you would never hide your experiment in your sister's closet before bedtime!) You will find that the beans expand to more than twice their original size.

Why does that happen? The dry beans absorb the water to start the process of sprouting. The water softens the cells, and is absorbed into them by the process of osmosis. This causes the cells to expand, making the beans larger.

When your experiment is finished, put the beans into some water with some spices of your choice. Then bake some corn bread, and you are ready for a tasty treat.

Have a wonder-filled week.

Thoughts on Trees

This is another post that comes from the Science Photo of the Day. It worked well there, but has great potential for a full blown Experiment of the Week activity. To try this, you will need:

- a plant or some seeds
- a pot to grow the plant in
- potting soil
- a scale to weigh the plant, pot, and soil

We will explore how plants grow, by growing a potted plant. You can use a plant from your local garden shop, or you can plant seeds from your favorite plant.

Start by weighing the pot. Then put the soil into the pot and weigh it again. Finally, add the plant or seeds to the pot, and weigh it one more time. This will let us calculate the weight of the plant (weight of everything minus weight of the pot and soil) as well as the weight of the soil (weight of the pot and soil minus weight of the pot.) Be sure to write everything down, as we will need that information later.

Then all you have to do is get the plant to grow. Give it water, and plenty of sunlight, but don't add anything else. As the plant gets larger, weigh it again. You should find that it has gained weight, even though you have not added any soil. Where did that extra weight come from?

To find out, start by looking at trees. Don't just think about trees. Look out the window, or even better, go outside. Notice how big trees are. Wrap your arms around the trunk, and get a feel for how strong it is. Think about how much wood is in that tree. Think about all the leaves that it produces and drops on your lawn. Think about how heavy those leaves are when you rake them up and haul them away.

Where does all that stuff come from? Your first thought is probably that it comes from the soil. After all, our bodies build up their mass from the food that we eat, and plants eat by taking in nutrients from their roots, don't they? Think about that for a minute. Look at the ground around the tree. If the tree had removed enough matter from the soil to build its trunk and branches, there would be a huge hole around the tree. Then think about your potted plant. It gained weight, which did not come from the soil in the pot.

Plants are not like us. They don't take in food. Instead, they make their own food, through the process of photosynthesis. To do that, they need energy, which they get from sunlight. They also need hydrogen, oxygen, and carbon as the chemical building blocks to make their food. They get those chemicals from water (hydrogen and oxygen) and carbon dioxide (carbon and oxygen.) During photosynthesis, these chemicals are recombined to form sugar. That sugar can be used as it is to provide energy for the plant, or it can be converted into other substances such as starch and cellulose, which make up the trunk, branches, roots, and leaves of the tree. Almost the entire tree is made of the chemicals from rain water and carbon dioxide from the air, and the same is true for your potted plant. It is also true for apples, peaches, strawberries, etc. When you think about it, even chocolate is made from plants. The sugar from plants, and so is the cocoa. That means that chocolate is mostly made up of sunlight, water, and air! Sounds yummy to me!

Have a wonder-filled week.

Why Paper Burns

This week's experiment is a result of a question sent to me by a list member. It is one of those questions that seems so simple until you try to explain it. To get started, you will need:

- a strip of paper about 4 inches long
- a pan of water
- a match or lighter

Warning: This experiment uses fire. Never work with fire unless there is an adult with you. That gives you someone to blame if something goes wrong.

Hold the paper over the water. Use the match to light the end of the paper. Watch it burn for a second, noticing the light and heat coming from the flame. Then drop it into the water to put it out. Why does the paper produce that light and heat? Why does it burn?

The key to the answer is energy. There are many kinds of energy, such as heat, light, electrical, nuclear (pronounced nu-cle-ar, not nuk-u-ler), etc. The laws of thermodynamics tell us that we cannot make energy, and we cannot get rid of it. We can only change it from one form to another.

The light and heat energy of the burning paper had to come from somewhere. It came from the paper. Now, where did the paper come from? Paper is made from wood. And where does wood come from? Trees.

Trees are plants. Where do plants get their energy? From the sun. Plants use a process called photosynthesis to trap energy from the sun. They combine water, carbon (The black stuff left behind when you burned the paper.) and the energy from sunlight to make sugar.

This sugar is then used to make other chemicals. By connecting many sugar molecules together into a long chain, the plant produces cellulose. That is what wood is made of. A piece of wood is really just a big chunk of sugar. The chemical structure has been changed, so it does not taste sweet, but it still contains the energy that was put into the sugar. When you burn a piece of wood, the heat causes the molecules to come apart, releasing the trapped energy, as the light and heat of the flame.

If you take the piece of wood and mash it into a pulp, then you can process it into a sheet of paper. Although it looks different, it is still made of cellulose, so it still contains the trapped energy. Burning the paper releases the energy, just as it does when you burn a piece of wood.

Now, look at another piece of paper. You can't see the energy, but it is there, hidden inside. Science is hidden all around you, if you just take the time to wonder about things.