Science Labs and Outreach Programs

It is the end of the school year for us and it has been a very busy April and May. Chris and I finished our last science lab classes in April and now we are doing nonstop outreach programs!

In Chris’ Biology Lab, she taught Fungus Among Us, where 5th-8th graders learn about molds, mushrooms & yeast with hands-on activities.  They learned about different types of fungi, dissected a mushroom, and experimented with yeast.

Carbon Dioxide releasing from yeast

Yeast Balloon Experiment

Chris says that no matter how hopeful you are or how much sugar you add, the balloon wouldn’t levitate the bottle or spontaneously blow off.

In my Wildlife Lab, I taught Bugs in Balance.  The K-8th graders learned what “ingredients” make an insect, and their life cycles, and then got a chance to meet live insects up close and personal. 

We started out by learning that bugs mean different things for different people–usually, the term “bug” refers to small, creepy, crawlies like insects, spiders, millipedes, & scorpions.  Many people aren’t aware that there is an order of insects called Hemiptera, known as the “true bugs.” 

After talking about the true bugs, we focused on insects in general.  We came up with a recipe for creating an insect that included the following ingredients: 6 legs, 3 body parts, 2 antennae, an exoskeleton, and wings optional!  We examined the Madagascar Hissing Cockroach as an example of a wingless insect.  They also met up with a Giant Malaysian Katydid, a beautiful green relative of crickets and grasshoppers.

Katydid (Orthoptera Tettigoniidae 5x7) _emailable 7825
Creative Commons License photo credit: fireflies604

We looked at the life cycle of the butterfly and compared it to that of the cricket.  Butterflies go through a complete metamorphosis that includes 4 stages: egg, larva, pupa, and adult.  The cricket only has three stages called incomplete metamorphosis: egg, nymph, and adult.

To learn about the balance of insects in our environment, we talked about how they can be both helpful and harmul to humans.  The younger classes created a beehive mobile to remind us of how important honey bees are as pollinators in our society and about Colony Collapse Disorder.  The older classes built a mosquito out of pipettes, pipe cleaners, & bobby pins as we talked about how this insect can be a carrier of diseases such as Malaria and West Nile Virus.

It’s time to take a break from our classes as we close out the school year with 3-5 outreach programs a week.  This keeps us very busy!  We must prepare ahead of time to ensure we have all of the proper specimens (e.g. stuffed bobcat, echidna, shark jaws) and that the live animals are ready to go.  We must arrive early to load up our van and attempt traffic to get to the school on time.  Once we arrive, we set up our specimens on the table and mentally prepare which animals will we show in which order.  We normally take 6-8 live animals and do 25-45 minute presentations.  We see thousands of elementary students a year and answer quite the assortment of questions including “Is it real?” and “Where’s its head?”

Wildlife on Wheels

Chris displaying a rabbit for our Texas Wildlife program

As you can see, our animals keep very busy as educational ambassadors which in turn keeps us very busy caring for them.  I hope you have enjoyed this brief look into our lives here at the Museum.  We look forward to sharing with you our upcoming Creature Feature: The Mysterious Matamata.

Elephants and Chemistry

One of my favorite chemical reactions is frequently called “Elephant’s Toothpaste.”  It creates a LOT of gas from very little liquid, which makes an impresive show, and the main ingredient, hydrogen peroxide, is already familiar to most people. 

Here is series of photos of the Elephant’s Toothpaste reaction (sometimes very fun and very messy go together):

 etp-big-1.jpg      etp-big-2.jpg      etp-big-3.jpg       etp-big-4.jpg

If you ask someone what they use hydrogen peroxide for, they’ll usually tell you it can clean minor cuts and scrapes or that it’s good for household cleaning. 

When you pour hydrogen peroxide on a cut, what do you notice?  The first thing you’ll notice is that it stings a bit, but you’ll also see bubbles at the site of the cut. The bubbles are evidence that there is a chemical reaction; you started with one substance and ended up with something completely different (there was no gas before you poured the peroxide on the cut, and there were gas bubbles after, so the gas is new).

The formula H2O is almost universally understood as another name for water; this chemical formula indicates  two hydrogen atoms stuck onto every oxygen atom. Hydrogen peroxide’s chemical formula is H2O2, so you can think about it as water with extra oxygen attached. When you pour it on your cut, the hydrogen peroxide decomposes into liquid water (H2O) and oxygen gas (O2). The bubbles you see are oxygen bubbles.

In case you were wondering, oxygen atoms don’t like to hang around alone, so they bond to each other and that’s why we get O2 instead of just O.  If you are a person who counts atoms and you noticed that our atoms didn’t quite add up, you’re right; the balanced equation for the reaction is usually written:

2H2O –>  2H2O + O2

The large 2′s mean two of that whole atom (two hydrogen peroxide molecules can react to create two water molecules and one oxygen molecule). If the equation looks strange to you, don’t worry; just know that the molecules do the right thing.

What isn’t included in this equation is that the blood in your cut initiates this reaction (it contains an enzyme called catalase).

Something to try: 

If you have a bottle of 3% hydrogen peroxide at home, I have a project for you (if you are a kid, do this with your parents).

You need 3% hydrogen peroxide, yeast, dish soap, and a cup or bowl.  Most people face bigger hazards in the kitchen every time they cook, but it is a good idea to wear safety glasses or goggles just in case something splashes or falls and breaks, and hydrogen peroxide in your eye would definitely sting.

Put some yeast (I used about a teaspoon of quick-rise yeast) in the bottom of your container:

etp-yeast.jpg

Add enough water to wet the yeast and swirl it around or stir it a little:

etp-yeast-and-water.jpg

Now add a little dish soap and swirl or mix again:

etp-soap.jpg

You may want to set the container or a plate to help contain the mess before you add the hydrogen peroxide (I added approximately 1/4 cup (60 mL):

etp-hydrogen-peroxide-1.jpg

etp-hydrogen-peroxide-2.jpg

Here the hydrogen peroxide is starting to react and the soap catches the oxygen gas and it starts to produce foam.

But it keeps going:

etp-hydrogen-peroxide-3.jpg

And going:

etp-hydrogen-peroxide-4.jpg

And going:

etp-hp-5.jpg

And going:

etp-hp-6.jpg

The yeast contains catalase (your blood does too), and that helps the reaction happen faster, but the big thing to notice is that a small volume of hydrogen peroxide reacted to create a big volume of oxygen gas (the soap just helped catch it so we could see it better).  Any time you start with a liquid and make a gas, if the gas can expand, it will, and usually a lot.

Oh, and even though the reaction is called Elephant’s Toothpaste, please don’t try to eat it. Yuck!