Joyce Bordelon [Moos Elementary School]
States of Matter
Joyce passed around a handout: Investigating States of Matter by Making Ice Cream, prepared by Leora Baumgarten, Science Teachers Enrichment Programs, LTD 1998.
We measured these temperatures by taking the averages of three readings. We then removed the inside bag, and shared the contents among us, and ate them. The ice cream was delicious!
Well organized, as well as yummy! Thanks, Joyce!
Ed Scanlon [Morgan Park HS, Biology]
Dissecting Owl Pellets
Ed passed out a handout that contained the following information:
Owl Pellet DissectionThe Barn Owl (tyto alba) can be found living in barns or dark places in and around the forest. They are about 40 - 55 cm long and have a wingspan of just over a meter. It can be recognized by its pale color, long legs, and long, white, nearly heart-shaped face. It lives in holes in trees, banks, buildings, etc. It lays 5 - 11 white eggs when nesting. Its range includes Northern California, Colorado, Nebraska, Illinois, the Southern Gulf States, Southern Mexico, and Nicaragua. They are nocturnal-feeding, and sleep during the day. They prey upon almost any animal that is small enough to be swallowed whole. Owls have a special structure that prevents the indigestible parts of their prey (fur, feathers, bones, etc) from passing into their intestines. Instead, these indigestible parts are shunted to a storage pouch, where they accumulate. A few hours after consuming a meal, the owl coughs up the accumulated indigested material, which has been compressed into a pellet. A close examination of the pellet can reveal what the owl has eaten.
- Purpose: to find out what and how many animals an owl eats.
- Materials: owl pellet, white paper and cardboard, dissection tools, bone-sorting chart (pictures of skulls, jaws, shoulder blades, front legs, hips, hind legs, ribs, and vertebrae for rodents, shrews, moles, birds), glue.
- Soak the pellet in a beaker of water for a few minutes.
- Place the pellet on white paper.
- Using dissecting needles and forceps, separate the bones of the animals from fur and feathers
- Clean the bones of debris, and sort them according to type.
- Clean the skulls as thoroughly as possible, since these are the best bones for identifying prey.
- Record the kinds and number of prey that you find in your pellet on a data sheet, and on a chart on the board. After the class record has been completed, copy the class data onto your record sheet.
- Bones of the skeletons should be laid out on a piece of cardboard and glued to the cardboard. [Put your name on the cardboard.]
- If a barn owl produces one pellet each day, estimate how much food the owl would eat in a year.
- What kinds of animals did you identify in the owl pellet?
- What animals were represented most often? What common traits do these animals have?
- What biological relationships were you able to determine from your examination? Draw up a food web for the animals you found.
Ed obtained an Owl Pellet Kit, which also has explanatory materials, from Science Kit and Boreal Laboratories: http://www.sciencekit.com/Products/Display.cfm?categoryid=294048. Ed suggested soaking the owl pellets in water to soften them before dissection. He also recommended gluing any complete or nearly complete skeletons on construction paper to display --- white school glue works well for this. We found rodents, as well as one bird, in our examination. The posters provided in the kit were very helpful in the identification of bone fragments.
Once you get used to the idea, this is really fascinating! Thanks, Ed!
Marva Anyanwu [Green Elementary School]
Genetic Engineering II [handout]
Marva continued her previous lesson on genetic engineering, using construction paper cutouts with magnets on the back, so that they would stick nicely to our blackboard. She showed the basics of making a recombinant DNA molecule by using two colors of construction paper. The idea is first to cut out a piece of a given DNA strand with an enzyme: cutting. Then, we use another enzyme to cut a DNA piece from another organism, and insert that piece into the empty space of the first DNA, using still another enzyme: ligation. The complete process of moving a section of DNA from the genes of one organism to the genes of another organism is called Gene Splicing. In this way one constructs new forms of DNA: Genetic Engineering. For additional details see the website What is Genetic Engineering?: http://www.bootstrike.com/Genetics/Home/index.html or http://agbiosafety.unl.edu/basic_genetics.shtml.
Very nice, Marva!
An excellent last meeting, from beginning to end of semester!!
Notes taken by Ben Stark.