Month: May 2008 (Page 2 of 5)

A Fungus Among Us

The cool, wet weather we have been having has brought out some cool mushrooms.

(Photograph by Karen Gibson used with permission)

Quick, are mushrooms plants or animals?

If you say neither plants nor animals, then you know your stuff. Mushrooms were once thought to be plants, but mushrooms don’t make their own food. Modern investigations have shown them to be more closely related to animals. For instance, mushrooms have the protein chitin, which is also found in insects. But mushrooms aren’t animals either. For example, they don’t run around like animals do. In fact mushrooms are so distinct, they are now given their own Kingdom, the Fungi.

What kinds of organisms belong to the Kingdom Fungi? Most people recognize that mushrooms are fungi.

In addition, yeasts and truffles, molds, mildew and also disease-causing parasites of insects are fungi. Lichens, which grow on rocks in a variety of climates, are a mix of fungi and algae growing together.

Fungi range in size from microscopic to quite possibly the largest organism on earth. Scientists are making the case that a giant fungus found growing in the Malheur National Forest in Oregon could be the world’s largest individual organism, because it covers some 2200 acres. Information is still being gathered, and because much of the fungus is hidden from view, it also could be made up of clusters of individuals.

The mushroom that we see is called a fruiting body. The fruiting body is like the flowers of a plant because it is how how a fungus makes more of itself or reproduces. The rest of the fungus is made up of threadlike strands called hyphae which form a mat called the mycelium. The mycelium is often hidden within the tree or soil and may grow for years unseen by humans.

If the mushrooms are like flowers, then where are the seeds? It turns out that fungi grow from tiny particles called spores. If you have ever found a mature puffball and stepped on it, the smoky clouds that come out are the spores being released into the air.

(Photograph by Sheila Brown Publicdomain.net)

Here is a picture of a puffball, if you have never seen one.

When the spores land on an appropriate surface, they produce strands called hyphae and then mycelia to develop into a new fungus.

Activities:

1. Fungi as Food

Explore edible mushrooms by visiting a grocery store to see all the different kinds that are available. We found shiitake, oysters, white, brown and portabellas. Discuss how the types are similar and different (some kinds sold under different names are the same species, simply more or less mature versions.)

You might want to buy a few different mushrooms, and try the different flavors in your favorite recipes. You could also pick up some yeast — another fungus– and make bread with it. Show the yeast to your children and let them smell it. By the way, there is nothing better than white mushrooms sautéed in butter made into a sandwich between two slices of freshly made bread.

Caution about wild mushrooms:  Because some species of wild mushrooms can be poisonous and make you sick, it is best to leave collecting to real experts. Some of the poisonous ones can closely resemble edible ones.

2. Make Spore Prints

If you don’t want to eat the mushrooms, use a few different kinds of mushrooms from the grocery store to make spore prints. Try to find older mushrooms already producing the brown powdery spores. Young mushrooms with pink gills or button mushrooms aren’t ready to make spores yet.

Place the mushroom with the frilly gill side against some white paper and then cover it with a glass or bowl. (You’ll have to remove the stem first). Leave for a few hours or overnight. If the mushroom is producing spores, it should leave a print when you gently lift it away.

Scientists who study fungi, called mycologists, use spore prints to help figure out what species they have found.

 

Related:

We have a newer post about yeast with activities.

If you have the time, growing mushrooms from a kit can be an amazing experience for kids. Kits are available with different types of mushrooms, at varying sizes and costs. They usually require certain conditions for optimal growth, so make sure you can provide that. Check the Internet for sources.

Interested in learning more? Check our growing list of children’s books about fungi at Science Books for Kids.

 

 

Bug of the Week: Tarantula Hawk

Today is overcast and windy, and most insects are settled in for the day. When I went out to search for the bug of the week, I was lucky to find this large insect resting on our milkweed plant. Being cloudy with gusty winds, it wasn’t easy getting a photo that was in focus. Here’s my best shot.

tarantula hawk

Check out the beautiful orange colors on the wings and the spiny legs. If you don’t recognize it, this is a tarantula hawk wasp. Belonging to the family of wasps known as the spider wasps, the tarantula hawk female searches for large spiders. When she finds one, she stings it and then drags it to a burrow she has prepared. Inside the burrow, the wasp lays eggs on the spider. The spider is still alive, but paralyzed. Over time it becomes baby wasp lunch.

Now take a look a something else. Can you see the yellow bit hanging from one of its feet? It isn’t in focus, so it may not look like much.

Here is a photo of another tarantula hawk wasp I took last year. Maybe you can see the bright yellow bits on the tips of its front legs more clearly. They are in pairs, and curve sort of like tiny maple keys.

The tarantula hawk has a special relationship with the desert milkweed plant. Its slender legs fit into special grooves in the flower while it is drinking nectar. The grooves contain bundles of pollen called pollinia. The pollinia catch on the wasp’s legs. When the wasp flies to another milkweed plant, the pollen is transferred and the plant is pollinated.

If you look closely at this wasp you might be able to see the mud on its body where it has been digging its burrow, or perhaps from when it emerged from the burrow its mom built.

For some live action videos, go to You Tube and search for tarantula hawk wasp. In one video, tarantula hawk wasp vs. wolf spider, you can see a wasp trying to drag its spider back to its burrow. Now, that is quite a sight!

Making a Science Boredom Bin

Who hasn’t heard the whine of “I’m bored” from their children, particularly during the quiet summer months? Usually it is enough to say, “Go try…” but sometimes they may need a bit of help to get started on a new project. This often happens in the late afternoon when we’re all tired, and the weather is keeping us confined to the house.

To combat the occasional summer blahs, I have been making what we call a “boredom bin” each spring. When I visit dollar stores or secondhand shops, I pick up inexpensive items like puzzles, games, books and art supplies, and throw them in a bin hidden in my closet. Once tedium reaches maximum levels, someone requests a trip to the boredom bin. I suspect just the anticipation of something new helps. Each child gets one item without seeing what else is in the bin. No matter what it is, off they run to play with it. It is a very happy tradition at our house.

This year I’m taking things a step further and making a science-themed boredom bin. Having recently heard a mother explain how she finally had saved up enough money to buy an expensive science kit for her children, I want to emphasize you can do a lot of science with things around the house that don’t cost much at all. Here are some ideas:

Because our family is studying the physical sciences, the first list is a physical science theme.

1. Inexpensive kites (often available in grocery stores for just a dollar or two), or balsa, string, tape and paper to make kites
2. Straws to make into kazoos, atomizers, droppers, bridges, you name it
3. Paper towel tubes, file folders and boxes to make marble towers, houses, airplanes, etc.
4. Plastic bags, bits of yarn or string, and action figures to make parachutes
5. Balloons to make cars, hover craft, drums, etc.
6. Inexpensive magnet and electricity kits, available used or at discount stores that sell returned/discontinued items
7. Inexpensive kitchen scale (garage sales) or materials to make a homemade scale
8. Flashlights, thermometers, magnifying lenses, prisms (we got a very inexpensive crystal pendent that works), aluminum foil to study light and heat
9. Building blocks and wheels (like Legos, Knex or Megablocks) (garage sales)
10. Plastic bins, toy boats, clay, soap, foil etc. to study floating and sinking
11. A good book of science activities to get you started, often available used

A chemistry-themed bin might include:
1. A box or two of cornstarch, to mix with about equal parts water to make cornstarch goo. Kids of all ages love to revisit this messy activity again and again.
2. Bubble mix or try the bubble science experiment in this blog
3. Pennies, nails. Add lemon juice from the kitchen to clean the penny, and copper plate the nail. Lemons can also be used to make invisible ink and with cabbage juice to explore acids and bases (see color experiments in this blog)
4. Oil, food coloring and water to study oil and water separation
5. Vinegar and baking soda to make volcanoes and rockets. For an incredibly simple, yet effective volcano: Have your child make a volcano shaped heap in a sandbox or loose soil, if no sandbox is available. Make a hole in the top, about 1 1/2 inches deep, and pour in some baking soda. Then pour in about 1/2 cup vinegar and stand back for the eruption. The cone can be rebuilt again and again. Add red food coloring to the vinegar to simulate lava.
6. Yeast packet, sugar, balloon and a water bottle. Mix the yeast, sugar and water in the bottom of the water bottle and then cover the opening with the un-inflated balloon. Watch what happens as the yeast begins to grow.
7. Metal objects such as nails, washers, paper clips, etc. Place in jars with either plain water, water plus salt, or plain vinegar and see what happens.
8. A good book of science activities to get you started, often available used

If you want a biology-themed bin, consider adding:

1. Bug catching and viewing toys such as bug vacuums, jars and nets. Encourage your children to catch, observe and release.
2. Seeds to plant in recycled containers
3. Dried beans to soak and sprout
4. Simple kits to make bird houses, feeders. Get more ideas from the bird watching activity in this blog.
5. String, measuring tape, pencils and paper, crayons, camera to study a tree. Keep a nature journal to see how the tree changes from season to season and over the years. Use the string to measure around the trunk and the tape to figure the length. Record what animals visit the tree. Make bark rubbings and press a few leaves. Check the tree flower activity, too.
6. Consider constructing a worm bin to recycle food waste. Red wiggler worms are the special type used in worm bins.
7. Gather materials to start and study a compost heap.
8. Herb seeds and pots to start an herb container garden. Kids like herbs because of their wonderful odors and textures, plus many herbs are hardy to grow, giving children success.
9. Inexpensive tape recorder. Tape insects, birds, mammals and frogs making noises, singing and calling.
10. Find a good book of science activities to get you started, often available used

Please let me know if you want further instructions for any of these projects, or if you have additional items to add to the lists. Good luck and hope you have a happy summer filled with science fun.

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