Pin the Organ on the Human

(Disclaimer: No actual pins were used.)

A student from the audience (blue shirt) prepares to pin the large intestines.
Pinning the large intestines.

One of my student groups came up with an excellent way of presenting the organs of the digestive system in Biology class. They drew an outline of a person on the board and then had students in the audience stick drawings of the different organs onto the outline.

What worked particularly well was that they’d have someone from the class pin on the organ, and then they’d talk about it. This gave the presentation a nice rhythm, with a little break between each item.

The organs pinned on the human.
The organs pinned on the human.

Thinking About Science Makes You Act Morally

… the association between science and morality is so ingrained that merely thinking about it can trigger more moral behavior.

— Valdesolo, 2013. Just Thinking about Science Triggers Moral Behavior

Piercarlo Valdesolo reports on an interesting study into people’s perception of science as having an, “emphasis on truth-seeking, impartiality and rationality privileges collective well-being above all else” that causes people to act more morally after thinking about science.

So, I’d be curious to see if this means that students act more morally in science class.

On Enzymes and Temperature

While discussing homeostasis in biological systems, one of my biology students asked why humans could only survive with only a very narrow range of body temperature. Part of the answer is that the human body is a complex system, and the chemical reactions rely on enzymes that only work effectively within a narrow range of temperatures.

Worthington Biochemical has detailed (probably too much so for our purposes) introduction to enzymes: how they work, how they’re named, etc.

In particular, they have this useful graphical diagrams showing how enzymes have an optimum temperature and pH.

Enzymes work best within an optimum range of temperatures. Image from Worthington Biochemical.
Enzymes work best within an optimum range of temperatures. Image from Worthington Biochemical.

Rabbit Dissection

Yesterday, Dr. Sansone was kind enough to lead my Biology class through a small mammal dissection (details here). He’d brought in five New Zealand White rabbits (2 male and 3 female) that had been raised for market by an Amish family in northern Missouri.

Over our two-hour class period, we had time to examine the organs in the abdominal and thoracic cavities in some detail. Students had been prepared with group reading assignments of the different organ systems based on the anatomy outline.

Dr. Sansone points out a rabbit's ovaries. A kidney is visible to the lower right.
Dr. Sansone points out a rabbit’s ovaries. A kidney is visible to the lower right.

After the dissection we removed the pelts and froze them for later preservation. We also froze the carcases for later. I’ve convinced Mr. E. that cooking them would be a great interim activity. Mr. E. is a bit of an epicure, so it did not take much convincing.

Notes

Only one student declined to participate in the dissection for ethical reasons. About half of the class declined to observe the harvesting. Four students volunteered to assist in the harvesting, two of whom were not even in my biology class. They were seniors. One of them, P., had done it before and demonstrated the procedure for us.

An Outline for Anatomy

Concept map for the study of anatomy.
Concept map for the study of anatomy. This diagram will be used for the introductory lesson.

Because we have the opportunity to get a few rabbits, we’re starting Biology this year with anatomy. In the first week, our discussions will be based around the rabbit dissection so we’ll be focusing on the systems where the organs are easiest to find: the fluid regulation/excretory, respiratory, cardiovascular, reproductive, and digestive systems.

A Concept Map for Mathematical Functions

Analyzing functions.
Analyzing functions.

This year I’m trying teaching pre-Calculus (and it should work for some parts of algebra as well) based on this concept map to use as a general way of looking at functions. Each different type of function can by analyzed by adapting the map. So linear functions should look like this:

Adapting the general concept map for linear functions.
Adapting the general concept map for linear functions.

You’ll note the bringing water to a boil lab at the bottom left. It’s an adaptation of the melting snow lab my middle schoolers did. For the study of linear equations we’ll define the function using piecewise defined functions.

The rising temperatures in the middle of the graph can be modeled with a straight line. Graph by A.F.
The relationship between temperature and time on a hotplate. The different parts of the graph can be defined by a piecewise function. Graph by A.F.

How to Give Effectively

Over the weekend I ran into this article from Planet Money/This American Life about a charity that just gives money directly to people. It should help to prepare my students for the Heifer International Ranch trip next month. It’s interesting to hear what people spend the money on; things like metal roofs and cows. Heifer gives cows and training instead of just cash. The article compares and contrasts the two approaches.