Quick and Easy Carbon Cycle Lesson

Are you looking for a quick and easy carbon cycle lesson, one that will tie in climate change and Greenhouse Effect? It would be a plus if it’s engaging too, right? Well, here’s one you can download and give your students to cut out and assemble. The pictures are interesting to look at, and enough clues are built in that you can even use this as a way to introduce the topic. It’s one of Speak Easies’ new Downloadable Kits, available here on our website very soon and on our store, Speak Easies Active Learning Tools for Biology at www.TeachersPayTeachers right now! It’s called the DIY Carbon Cycle. It’s highly effective as a learning tool, because it relies on the kinesthetic mode– it’s hands-on. As kids assemble the cycle, they draw on prior knowledge, educated guesses, and the included backstories for the pictures to put it together.

Excerpt from Key to the Pictures in the    DIY Carbon Cycle Downloadable Kit

So what is included in the kit? Two pages of engaging pictures to cut out, a two-page key to the pictures, giving the backstory for each, two pages of pro tips for you with suggestions for using the kit to teach the topic, a page of questions to discuss, and an answer key, including a picture of the assembled carbon cycle. These are the topics the pictures address: photosynthesis and cellular respiration, combustion and burning of fossil fuels, decomposition, fossil fuel formation and extraction, carbon sequestration, soil as a reservoir for carbon, role of native grasses in sequestration, greenhouse gases–both carbon dioxide and methane emissions and their impacts. And of course, as students work with the pieces they will see the ways to reduce impacts and trap carbon away from the atmosphere.

Carbon Cycle Assembled from Pictures in the Kit

Beautiful Foliage, But the Rash Isn’t So Pretty!

Here’s a picture of beautiful fall foliage in the oak woodland in Annadel Trione State Park in Northern California, and the striking plant is— poison oak! Lots of people suffer itchy rashes when exposed to the oil it contains, urushiol. The Native Americans who live where poison oak is found have long made use of it in basket-making, dyes for tattoos, and medicines. Apparently they developed some immunity to it, though they also made medicines to treat its rash.

In spite of its name, it’s not actually an oak. It does play an ecological role, providing food for many birds and small mammals, as well as deer and insect larvae. It also helps to anchor slopes and prevent erosion. And it’s a pioneer species, meaning it is one of the first plants to return after a disturbance like a wildfire. Since climate change is leading to more and more wildfires, we can expect to see more poison oak in the future.

Photo courtesy of Neill Fogarty.

Salt Marsh Returns to San Francisco Bay! Why Does It Matter?

Looking north across San Pablo Bay (part of San Francisco Bay). In the foreground is ancient salt marsh.

This is ancient salt marsh, a remnant of wetlands that used to surround San Francisco Bay.  Only 5-10% remain.  All around the bay, environmental non-profits are working with citizens to restore wetlands.  Transition zones and marshes are being planted, and levees are being breached.  Eventually wetlands will once again surround the entire bay.

But why does it matter?  After all, sometimes the existing marshes and mudflats are pretty smelly, but that is a sign of the richness of living things being nurtured there!  Here are just a few of the ecosystem services provided by wetlands.  In the wetlands, marshes and estuaries, the soils sponge up water and release it slowly, helping to mitigate flooding.  The marsh plants’ roots form a mesh that traps sediments and pollutants flowing into the bay from creeks and rivers.  Wetlands act as nurseries for the immature larvae of many different species–some of which, like crabs and fish, are commercially valuable, and all of which play roles in the ecosystem.  There is much more (Google!) but here’s one that’s of huge importance:  wetlands, mudflats, and marshes act as a buffer zone, protecting areas further inland from storm surges and sea level rise.  And here’s another service they provide that is vitally important:  salt marshes and mudflats are especially powerful in carbon sequestration!

No Males Need Apply: Parthenogenesis in Gall Wasps

In some gall wasp species there is reproduction without males!

The title might sound scholarly, but what does it mean?  Parthenogenesis in animals is the development of an embryo from an unfertilized egg cell– in other words, no males involved.  This can happen among some invertebrate species, and even in some reptiles and amphibians.  With gall wasps, the males and females reproduce in the conventional way in the spring, but in the fall the females manage it all by themselves.

Of course, the practice of parthenogenesis decreases genetic diversity, as you would expect, but it has some advantages too.  For one thing, it usually results in production of much larger numbers of offspring, possibly because less energy is expended in looking for a mate.  Imagine being free of those pesky mating rituals!   The time and energy you’d save by not dating!

And here’s a cultural  aspect to consider:  a friend who is a member of the Coast Miwok tribe told me the tribe used to carefully time their controlled burns to hold down populations of these insects.  Clever.

Find out more about gall wasps and all other things related to oak trees in this wonderful book:  “Secrets of the Oak Woodlands” by Kate Marianchild.

Fierce Predators and Sharp Teeth

It’s all about attitude!

So you were expecting maybe –sharks?  Barracuda?  Well, no.  Here you see some creatures to be reckoned with, and they all live in our California kelp forests.

The purple-ringed topshell, Calliostoma annulatum, though tiny, will even rear up on its foot and lunge at its prey!  Of course, its prey might be kelp, a copepod, an anemone, or even some dead fish, but still.

Then there’s the sunflower star, Pycnopodia helianthoides, a giant sea star, as large as 40 inches across, with more than twenty arms at maturity.  It preys on urchins, crabs, sea cucumbers, snails and chitons.

So where do the sharp teeth come in?  The purple sea urchin, Strongylocentrotus purpuratus, has sharp teeth on its underside and is able to use them to erode holes in rocks!

BTW, see the pictured animals, featured as magnetic manipulatives, in Speak Easies’ Kelp Forest Food Web, coming soon on Teachers Pay Teachers.

Sex Change: One of Nature’s Strategies

Here is a picture of a sheephead fish (Semicossyphus pulcher) and he has an interesting story to tell, because, though he’s a male, he used to be a female!  Turns out changing sex is not uncommon among fish; there are many species that do it, and some,  like the                              

A sheephead male on the prowl.

sheephead, go from female to male, while others go from male to female.  In the case of the sheephead it is thought that females reproduce most when they are small, but when the fish gets large, males have the reproductive advantage, thus the change.  This is called serial hermaphrodism.  When it comes to maximizing reproduction, to quote Jeff Goldblum in Jurassic Park, “life will find a way”!

Nitrogen Fixing Bacteria Need Nitrogenase–Why Should You Care?

All us animals need a constant supply of nitrogen for our cells to use to make protein for repair, growth and maintenance.  Good thing the atmosphere is more than 70% elemental nitrogen.  But wait, we can’t use elemental nitrogen!  Uh oh!  How do living things get it then?

There are a few species of bacteria that can “fix” nitrogen, converting it to a form that can enter the food chain and be used by plants and us voracious consumers.  So where does nitrogenase come in?  That “ase” ending is telling us that it is an enzyme, a biological catalyst that makes chemical reactions possible in living things, and the nitrogenase enzyme catalyzes nitrogen fixation reactions in those particular bacteria.  Okay, so what?  Take another look at that bucket…

…Yes, that vitally important enzyme, crucial to life as we know it, could all fit in one bucket.  All of it.  All around the planet.  So this critical ecosystem service, nitrogen fixation, depends on certain bacteria that in turn depend on nitrogenase enzyme.

Makes me want to keep those bacteria very happy, in a clean and healthy environment, with enough good-quality nitrogenase to fill their needs, so they can fill my needs.  (Enlightened self interest at work.)

Fun Fact About Rubisco

But what is rubisco?  Rubisco, ribulose bisphosphate carboxylase, is the enzyme responsible for the regeneration of RuBP as well as for the formation of phosphoglyceric acid, PGA.  In the largest sense, rubisco supplies one of the most important biosphere services–making carbon fixation possible!  We say “give us some sugar” and rubisco goes into action!

You can see it in this photo of the Calvin cycle piece from Speak Easies’ Photosynthesis Kit.  It is shown as a wrench because lots of enzymes catalyze reactions by holding substrate molecules in a certain orientation to each other, you know–sort of like a wrench.

And now for the fun fact:  Rubisco is one of the most abundant enzymes on the planet!  If that isn’t fun, what is?

Where- and What- Is the Z-Scheme?

So, what is this Z-Scheme anyway?  Can you spot it below in the picture of our Speak Easies magnetic Photosynthesis Kit?

    The Z-Scheme is a handy graphic way to think of photosynthesis’ energy profile.

A photon of sunlight (680 nm) blasts an electron out of the chlorophyll in photosystem II and energizes it, propelling it through a series of molecules (the electron transport chain) where it releases its energy step-by-step.  That energy is captured in ATP.  Then another photon (700 nm) energizes an electron from a chlorophyll molecule in photosystem I, and that electron releases its energy in the manufacture of sugar.

This is discussed so clearly in a book by Nick Lane, “Life Ascending–The Ten Great Inventions of Evolution.”  Check it out.  And remember, you can have your students using our hands-on kit to enact the process of photosynthesis till they really get it!!

Did you spot it yet?

Turning the magnetic electron transport chain piece reveals the Z-Scheme.

And there it is!  The Z-Scheme!  Probably you already knew.  But having the separate pieces of this magnetic kit will make it easier to show your students, or better yet, challenge them to show you!

 

 

 

Seeing Stars! The Mystery of the Sea Star

A beautiful example of radial symmetry!

Such a strange, elegant creature—the sea star!  The mystery:  its tiny larva, floating in the plankton, has bilateral symmetry, but its adult form is radially symmetrical—a radical transformation!  How could that happen?  Donald Williamson, an English zoologist, suggested a theory of “larval transfer”, saying that in the past, genes for body shape and for life cycle were exchanged when hybridization occurred between marine species with the two distinct body plans.  This would be possible due to external fertilization, which, in the ocean means millions of sperm and eggs of different species are floating around and bumping into each other.  Williamson demonstrated in the lab that cross-fertilization between species is possible in those circumstances!

Note the radial symmetry in the adult vs. the bilateral symmetry in the larva.

 

See Ryan, Frank, “The Mystery of Metamorphosis—A Scientific Detective Story”, White River Junction, VT, Chelsea Green Publishing, 2011, print