Category Archives: Biology

MMcC and DW – Taxonomy

MMcC had an assignment to look at the taxonomy of various creatures.  She and DW set to the task.  It was far tricker than they thought it would be.  Here is their result.

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Filed under Biology, DW, MMcC, Science

Going Out to Charlotte

Tomorrow morning we are all heading to Charlotte, NC.  We are going to see Discovery Place’s display of mummies.  They have both desert and cave mummies, salt mummies and bog mummies.  I can’t wait to see and compare all these different types.

From Discovery Place web site.

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Filed under "Coming of Man", AV, Biology, BW, DW, Geography and World Studies, Going outs (Field Trips), JV, MMcC, Science, Students

All in a Day’s Work

One of AV’s jobs at the S.C. Aquarium is to identify specimens that are brought in by patrons.  He has become adept at skull ID and even asked for this App for Christmas. (I can not encourage you enough to get this app!)  He also uses the Skulls Unlimited Catalogue (worth getting, too)!

Recently, when we were hunting we ran across a partial skeleton. AV put it aside to work with at the Aquarium.  It took about four hours to assemble these front paws.

Initially we thought it was a fox.  As he assembled the bones, it became obvious that the paws were not formed in the manner that we thought the fox’s would be formed.

AV’s boss was great and began looking for a coon’s paws.  No dice. He found an image made in the 1700’s that was not good enough quality to use as a road map.

So back to matching bones from scratch.  Eventually almost all the bones were assembled to form the two front paws of the coon.

I think he is ready for the archeology trip next week!

 

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Filed under AV, Biology, Practical Life - Elementary, Projects, Science, Students

DW: Sugar Gliders Compered to Flying Squirrels

Sugar gliders and flying squirrels look alike and live a similar life style.  My family and I discovered a creature in the attic.  We narrowed it down to two animals, a sugar glider and a flying squirrel.  Using observation and information at hand, we discovered it ate nuts and formed a theory of which animal it was.

Sugar Gliders compared to Flying SquirrelsSugar gliders are marsupials.  They are native to Australia and Indonesia.  Sugar gliders are rare because people will cut down trees, and destroy sugar gliders habitat.  Since sugar gliders live in cavities in the trees, the cut down trees will leave the sugar glider falling to their doom.  For these reasons, it is illegal to even to touch or get to close to a sugar glider in Australia.  Sugar gliders feed on insects and fruits.  Sugar gliders also eat sap, nectar, or anything else sweet.  Export or breeding of sugar gliders is illegal, but people export them illegally.  Now people in the United States are breeding them, and sugar gliders have  become popular pets.

Flying squirrels are found all over the North American Continent.  Flying squirrels are common, but are not see because they are nocturnal.  They make nests in birdhouses, tree cavities, high-up holes, abandoned buildings, and attics.  Flying squirrels feed on nuts, fruit, sap, bark, seeds, and insects.  There are many predators to flying squirrels such as: owls, cats, raccoons, snakes, and fishers. Flying squirrels are often pets.

Both flying squirrels and sugar gliders are similar in size.  If you held both a sugar glider and a flying squirrel together they would fit into you hand.  With eyes to big for their body it makes them look super cute.  These eyes help them see in the dark.  The both have a flap of skin and a flat tail to help them fly.  The flap of skin is called the patagium, and stretches the front wrist to the back wrist.  They both have extremely soft fur.  Their tail not only help the fly, but adds to it’s cuteness.

Although sugar gliders and flying squirrels have a lot in common, they also are different in many ways.  For starters sugar gliders are marsupials, flying squirrels are squirrels.  They both live on opposite sides of the earth.  The facial markings are different, sugar gliders have a stripe down their face ending on their back.  Also their ears are pointy, like elves.  The foods they eat are different than the other.

You might have guessed, we thought it was a flying squirrel.  The flying squirrel is now released and back into the wild.  So it was a happy ending, because we learned about something, the squirrel learned something (never go into an attic.) And we had an experience we would never forget.

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Filed under Biology, DW, English Language, Science, Students, Writing

Goings Out and Getting Busy – Part I

We are so blessed to live in a college town.  In the next month and a bit, there are a lot of lectures that we are going to go absorb.  Darwin Week is one of our favorite series of lectures.  Last year it brought us the  Blood Sucking Flies lecture and the year before an amazing talk about Neanderthals.  Since we are located in “The Holy City,” it is appropriate that the Darwin Week include a discussion of faiths and the coming of the universe.  This year the them is “Does Evolution Lead to Evil.”

The Evolution of Complex Animals: New insights into some very old problems in evolution.  

Monday, February 6 at 4:00 p.m.   CofC School of Sciences and Math Auditorium          Dr. Athula Wikramanayake

Over 500 million years ago, the Cambrian “explosion” yielded a remarkable diversity of animals with bilateral symmetry — animals which have evolved to constitute 95% of the world’s fauna today. Did such complex “bilaterian” animals evolve from simple, non-bilaterian organisms?

Need for Speed:  The Evolution of Decision-Making in a Rapidly Changing World

Tuesday, February 7 at 4:00 p.m.    CofC School of Sciences and Math Auditorium          Dr. Catalin V. Buhusi

Despite our sophisticated cognitive abilities, humans are notoriously bad at making rational decisions. Similar biases, aversions, and reference-dependent choices have been reported in other species, suggesting that evolution has shaped our ancestors’ brain to make decisions in a different kind of environment. How can we reconcile the apparent necessity of rapid decision-making with the need for building a long-term sustainable society for future generations?

THE 2012 TALKS ON TAP DARWIN WEEK EVENT:  Does Evolution Lead to Evil?  Two Christian Perspectives

Tuesday, February 7 at 7:30 p.m.      Second Presbyterian Church    Dr. Brad Harrub and Rev. James B. Miller

Critics have claimed that regardless of whether evolution is true or not, to believe that humanity had its origins in earlier non-human species leads to racism, eugenics, euthanasia, abortion, and youth violence. Join Rev. Jim Miller and Dr. Brad Harrub for a fascinating conversation on the potential ethical implications of evolutionary theory, with a robust question and answer time to follow.

Astrobiology:     The Search for Life in the Universe

Wednesday, February 8 at 4:00 p.m.     CofC School of Sciences and Math Auditorium       Dr. Luke S. Sollitt

Are we alone in the Universe? Until recently, this fundamental question about humanity’s place in the cosmos was the province of philosophy or science fiction. The nascent science of Astrobiology seeks to turn science fiction into science research, and answer it once and for all. Dr. Sollitt will discuss three main research areas in this new field: the search for habitable planets elsewhere in the universe, the study of so-called “extremophiles” on Earth, and the search for habitable zones and life elsewhere in the Solar System.

The Ice-Age Dispersal of Humans to the Americas: Do Stones, Bones, and Genes Tell the Same Story?

Thursday, February 9 at 4:00 p.m.          CofC School of Sciences and Math Auditorium        Dr. Ted Goebel

When did modern humans colonize the Americas? From where did they come and what routes did they take? These questions have puzzled scientists for decades, but until recently answers have proven difficult to find. New techniques of molecular genetic analysis, and a reinvigorated search for early archaeological sites across the western hemisphere, recently have led to some astounding results.

 

 

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Filed under "Coming of Man", Astronomy, Biology, Geography and World Studies, Geology, Going outs (Field Trips), Physics, Science

Nitrogen Cycle Montessori Style

The Montessori Elementary child is presented with a number of lessons about plants.  We have previously discussed the first 2 lessons of plants: 1.  The Four Greek Elements and 2. What Nutrition Plants Need.  These serve as an introduction to the idea of chemistry to the Elementary child.  We’ve discussed the historical practice of leaving ground fallow and the modern practices of fertilization (with the example of cotton in the post Civil War south as the prime example).  The third of these lessons is a discussion of Nitrogen and the Nitrogen Cycle.  There are diagrams of each of the lessons that were created after Dr. Montessori did by a number of her followers.  These diagrams lack the elegance for which Montessori works are known.  Perhaps the most unsettling of the diagrams is the Nitrogen Cycle’s.  So, Mrs. W and I worked out a hands-on work.  We are open for suggestions.

Materials:

  1. Chart 2 of “Plant nutrients”.
  2. Jar of air.
  3. Soybeans, peanuts or other legumes
  4. Chart 3 – nitrogen cycle in felt parts.
  5. 4 boxes with the parts.
    1. “Free Nitrogen”
      1. 10 tickets labled “N”
      2. 10 tickets labeled O
      3. 10 tickets labeled H
    2. “Nitrification box 1 – atmosphere”
      1. Cloud in grey felt
      2. Rain
      3. Lightening with two branches
    3. “Nitrification box 2 – terrestrial”
      1. legume stalk and roots
      2. legume leaves
      3. nitrogen fixing bacteria
      4. deer
      5. poop x 2
      6. earthworms
    4. “Denitrification”
      1. green leaves
      2. brown leaves
      3. bones for deer
      4. denitrification bacteria
      5. fungi – mycelia and mushroom
  6. Jar with soil.

Nitrogen Cycle Presentation:

Lay out the underlayment and place underground water table, tree, sun and clouds in their places.  Open “Free Nitrogen” box.

Plants, like all organisms, require a certain number of chemical elements for growth.

The story of one of these, nitrogen, is an interesting one. Nitrogen is especially important because proteins are rich in it, and they carry out a lot of the work in the cells.

Take a deep breath.  Slowly breath it out.  Hold the glass of air up.

Even though 78% of the air we breathe is nitrogen, plants and animals can’t use the free nitrogen.

Lay out most of the Free Nitrogen cards in the atmosphere.

We breathe it back out.

Show Chart 2.  Invite the children to recall the lesson and name the elements.

And out of the 12 or so elements that a plant must obtain from the soil, only nitrogen can’t be obtained directly.  It must first be fixed – that is, combined with other elements usually hydrogen or oxygen.  This happens in a two main ways.  When nitrogen is fixed, it is called “Nitrification.”

Lay out the rest of the Free Nitrogen cards in the soil.

Open “Nitrification box 1 – atmosphere” box.

The first way nitrogen is “fixed” is in the atmosphere. The catch is that nitrogen will only bond with its favorite elements when there is high temperature and pressure.  Where in the atmosphere will you have really high temperatures and lots of pressure?

In lightening bolts!

Set out the cloud and place the H2O tickets in the cloud. (4 H2Os)

Lay out rain.  Move an H2O into the stream of rain.

When the lightening bolts strike the nitrogen bonds with oxygen making Nitric oxide.

Lay down the lightening bolt.  Move the first H2O near one branch of the lightening bolt and bring a N over to the H2O, split it apart and allow the H2s out into the atmosphere.  Join the N with the O.

Move the second and third H2Os near the second branch of the lightening bolt and bring over a N, split it apart and allow the H2s out into the atmosphere.  Join the NO2 together.

When the NO2’s fuse this is called nitrogen dioxide.  The Nitric oxide falls to the ground with the rain.  However, not all of the nitrogen dioxide falls directly to the ground.  It bumps into some of the H2O’s.  It then fuses and forms nitric acid.

Move the NO2s with waters and arrange them into nitric acid.  Make sure all the nitric oxide, nitrogen dioxide, and nitric acid move into the soil.

These three types of fixed nitrogen that are made in the atmosphere are may be used by plants.  This is three ways Nitrification takes place in the atmosphere.


Move one of the nitrogen dioxides into the trunk of the tree through the roots.

Open “Nitrification box 2 – terrestrial” box.

In temperate soils, another types of fixation takes place in the roots of some plants.

Ask the children to name some legumes. Share the soybeans or peanuts.  While the children chew, lay out the legume plant.

As these plants grow, their root hairs send out certain chemicals that attract root bacterias.  When the bacteria touches the root hairs two things might happen.  1. if it is not the right type of bacteria the root protects itself for it.  But, if it is the correct type of bacteria, it is held there,

Lay out the bacteria in the soil and move them to the roots of the legume.

and a kind of tube grows from each bacteria into the cells of the tiny root hairs.  These bacteria enter into the cells and reproduce causing a swelling called a “nodule” on the root.

Move the bacteria onto the roots.

This is not an invasion that will hurt the plant.  The bacteria and the plant are working together.  Do you know the word that is made from the Greek word sym meaning together and the word bios meaning life?

The plant provides energy in the form of ATP and the bacteria bring an enzyme that takes the fixed nitrogen and combines it with hydrogen and that makes ammonia!

Move the NO2 to the plant’s roots and combine it with Hs from water to make NH3

The ammonia is quickly converted into NO2 and NO3.  Plants use these as fuel for growth.  It is incorporated into many amino acids when are used to make proteins.

Make the NO2 and NO3.

The Oxygen from the water is not wasted but used as part of the process and then released.  Nitrogen is stored in the leaves, fruit, and roots of the legumes  and remember that the fixed nitrogen that was made by the lightening can be used by other plants.  This is quite a bit of nitrogen hanging out in plants.  But man needs nitrogen, too.  How do we get nitrogen to help us grow?

Say a person, or a horse, or a deer comes along and sees some tasty soybeans or pulls up a peanut plant and finds tasty peanuts,  what do they do?       Ahhhhh.

Lay down the deer with him “eating” the legume.

Yes they eat it.  Now the fixed nitrogens are inside the deer.  I wonder how they might come out?

Lay down the feces.  The first at the anus of the animal and the second on the ground where it would fall.  Lay down the earth worms.

One way is for the animal to excrete waste.  The animal might be a tiny earthworm or a giant whale.  It still extracts what it can from its food; it can’t take all of the nutrients and some pass into the feces to be excreted from the body.

Open the “Denitrification” box.

We now begin the process of “Denitrification” – of breaking apart the fixed nitrogen into single nitrogen atoms to be used again.

Can you think of another way that the nitrogen trapped in a living thing can be returned to its denitrified state?

This may be difficult for the children to think through.  Give a second or two and lay the deer down so his main body is below the soil line.  Add the bones to the body.

What about the plants?  How does the trapped nitrogen leave the plants?

They will get it and will say that the trees and plants die.

Yes they do die,  but some trees live a very long time.  How about their leaves?  On most trees, they live only one year and then fall off.

Put the green leaves falling and the brown leaves on the ground near the deer.

What creatures have been given the special job of decomposition?

Bring out the mycelia and the mushroom,  bring out the bacteria, move the earthworms over.

Take the nitrogen and oxygen in the deer and break it apart and return it to the atmosphere.

Take the nitric acid in the tree and break it apart and return it to the air.  Put water back into the clouds and generally reset the cycle.

This important job of denitrification takes death and turns it back into what brings life and growth.  The cycle may begin again.

Touch the clouds and walk through the cycle again using the major terms.

Now that you have had this lesson you may do this work.  You must be very careful with so many ways and times that nitrogen fixes, you must be observant and thoughtful to cause the correct nitrification and denitrification at the correct time in the cycle.

FYI:

  1. Volcanoes,  power plants, and cars also can fix Nitrogen.
  2. A byproduct of denitrification is N2O or nitrous oxide, “laughing gas” and is considered a greenhouse gas.
  3. The oceans have their own nitrogen cycle which involves blue-green algae and other bacterias without having a symbiotic relationship with plants.
  4. Fertilizers and the Haber Process is its own topic and worth research by an upper el student.

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Filed under AR, AV, Biology, BW, Chemistry, DW, JV, Science, Students

Sight for the day

DW headed out to they yard for free time (also known as recess) and discovered this sad robin.

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Filed under Biology, DW, Practical Life - Elementary, Science, Students