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National DNA Day Friday April 20, 2012

Did you know it is National DNA Day this Friday, April 20, 2012? 

National DNA Day celebrates the completion of the Human Genome Project in April 2003, as well as the discovery of the double helix structure of DNA.

Of course I went right to the Teaching Tools to see what was available.  The NHGRI Activities for the USA Science and Engineering Festival link takes you to instructions for kid-friendly activities:

  • Craft a DNA Bracelet
  • Create Tree of Genetic Traits
  • Take The Genetic Challenge
  • Extract Strawberry DNA (see related post here)

Digging around, the Genetics Resources for Teachers has .pdf files to download. The Educator’s Page has links to a variety of resources, as well. Many of the materials are suitable for older children and young adults.

K8 Science has also put together some resources to honor National DNA Day.

I noticed the American Society of Human Genetics sponsors a DNA Day Essay Contest for students in grades 9-12 with cash prizes (it’s not clear whether it is open to homeschool students). Although too late for this year, it might be something to keep in mind for next year.

Why not take a few minutes and build a DNA molecule on Friday to celebrate?

Illustration from Wikimedia

Bug of the Week: Scorpions

Usually scorpions are active at night.

Once in awhile, however, you can spot one during the day.

This is a youngster. I can tell by its size.

Scorpions look very different from their relatives, the spiders.

(Line drawing from Wikimedia Commons)

The parts of a scorpion are not always easy to identify. For example, how many legs does a scorpion have? Does it have eight legs (as it should since it is supposed to be an arachnid), or does it have ten? What do you think after looking at the photographs and line drawing?

Answer:  Those two pincher-like appendages at the front are called pedipalps and are not considered to be legs. Therefore a scorpion does have eight legs.

Another feature of scorpions is that they don’t have distinctly separate body regions.

Perhaps this colored diagram will make it easier. In this case, the legs are colored  light green and the pedipalps are blue. The dark green area is the “head” region (called the cephalothorax). Do  you see the black dot that seems to be in the middle of the “head” region in the photographs above? Those are the median eyes, shown as red dots labelled “O” here. The scorpion also has lateral eyes on the front sides of its “head,” which you can see in the photographs. The darker blue appendages are the chelicerae, which are mouthparts.

The middle part of the scorpion is colored yellow and is called the mesosoma. The tail, colored in pink, is the metasoma. Finally, the business end is the bright red telson that contains the stinger.

Why do scientists identify and name the various parts? One important reason is to be able to describe characteristics of different species (and higher groups) accurately so that others are able to tell them apart, too.

Bet you didn’t think you would be looking this closely at a scorpion today. 🙂

Do scorpions occur where you live?

If you are interested in finding out more, try the middle-grade book Scorpions: Armored Stingers by Sandra Markle (link takes you to a review at Wrapped In Foil).

Reading level: Ages 9-12
School & Library Binding: 48 pages
Publisher: Lerner Pub Group (T) (March 2011)
Language: English
ISBN-10: 0761350373
ISBN-13: 978-0761350378

Scorpions: Armored Stingers (Arachnid World)

(Amazon affiliate link)

Mystery Seed of the Week 111

One of the joys of doing Seed of the Week is popping open the seed head or pod of a plant you’ve seen a million times and discover a fascinating seed that you never even knew existed.

That’s what happened today.

These seeds are from a common plant found in the Sonoran Desert.

Note:  these seeds may not be fully ripe, so they may be a bit darker in the mature form.

Any idea what plant these might be from? Extra credit for a whimsical description of what you think the seeds resemble. I think they look like they have a punk haircut. 🙂

Edit:  The answer and a better photograph of the seeds are now posted.

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