Archive for the 'AP Biology' Category

Ditch the Text. It’s Yesterday’s News.

I began teaching biology in 2008 and was given a book published in 1994 to distribute to my first group of AP students.  I recall thinking that I was 13 years old in 1994.  Could a book published at a time when I wore braces and carried a backpack that quite literally outweighed me still be an adequate teaching tool?  What I should have been thinking was how vastly different the world looked to a biologist in 1994.  Dolly the sheep was a mere fantasy, prokaryotes purportedly lacked cytoskeletons, and whole genome sequencing was in its infancy.  While the book clearly delivered basic concepts in biology, too much of its content was no longer relevant.  Moreover, omitting 14 years worth of progress in the field of biology would have been a huge disservice to my students.  A savvier instructor would have ditched the text completely.  As a new teacher, I found myself desperately clinging to the structure it provided.

Although I think the textbook’s starring role as the curricular centerpiece is nearing its finale, one cannot entirely dismiss a textbook’s value.  Teachers like textbooks because they:

  1. Provide an orderly, logical progression of topics for an entire course.
  2. Come with accompanying assessment and classroom tools.
  3. Cover a large breadth of content, which often helps ensure that courses meet curricular requirements.

Thus, for my AP course, even after the overhaul of the curriculum, I cannot envision giving up my (new) book completely. Furthermore, the iBook version of Miller and Levine‘s classic Biology text and others like it are models for all biology texts in the future.  They make excellent use of their digital platforms:

In addition to containing vibrant, interactive content, these iBook versions are also significantly cheaper than a hardcopy of the textbook.  Schools can subscribe to the book for one academic year and choose whether or not to renew the following year.  Assuming the digital books are updated frequently, this will help to keep only current texts in students’ hands.  However, even the most up-to-date textbook has drawbacks, including:

  1. Science advances rapidly, and the most relevant sources will continue to be science news and journal articles.  Even texts that are frequently updated will inevitably and swiftly become yesterday’s news.
  2. Technology teaching tools also advance rapidly, quickly rendering a text’s accompanying materials and activities obsolete.
  3. Most books survey a large body of material.  By attempting to construct courses that align with texts, teachers risk covering too much content even when it is not necessary or required.

I recall the first meeting I had with my school‘s new headmaster, Mick Gee, whose ideas about education are progressive.  He embraces change, unafraid of trying new things.   During the meeting, he inquired why I bother to use a textbook, challenging the dogma that textbooks are essential.  I teach at an independent school after all.  Why shouldn’t I take advantage of this independence?

This year I have seized this independence in my elective course, Genetics.  The students enrolled in this course have already taken at least one survey course in biology.  When I began the semester, I explained to the students that I felt no need (or pressure) to skim the surface of many topics in genetics.  Rather, I told them it was ok to spend more time on topics they enjoy.  We weren’t going to rush through things in the same way we needed to in AP Biology.  Their faces looked hopeful and relieved, setting a positive tone from the beginning of the year.

I’m happy with the course that we’ve created together.  It is undoubtably unique among high school science classes.  We’ve drawn heavily from current events, students have had a great deal of choice about what topics they explore and how they demonstrate their comprehension, and the atmosphere has been a collaborative one in which we all learn from each other.  Focusing on fewer topics has also enabled us to do a number of labs that require extensive amounts of class time.  A microarray  lab, a genotyping lab, and a Nasonia genetics lab have all been highlights.  Admittedly, since we have used our book on occasion as a reference tool, it probably isn’t fair to say that we ditched it.  However, it has moved out of the spotlight and into a supporting role in my Genetics classroom.

I hope to elaborate more about my Genetics course in future posts since we have had a productive and exciting semester. Independence feels so good!

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Joy Found Looking Through the Microscope Lens

Graduate students in biology work long, hard hours, often with little to no usable data to substantiate their efforts.  I remember having many frustrating moments, but with microscopy experiments, my reaction to negative results was often still upbeat.  Sometimes the images were so beautiful that they took center stage on my desktop even though they would never grace the pages of my thesis.

My love for microscopy does not make me unique among scientists.  Take Dr. Robert Rock Belliveau, a retired pathologist whose eyes never grew tired of the microscopic world.  In a post on Smithsonian.com, he stated, “I would go to work and spend ten hours a day looking through a microscope.  A couple of times a week, I would say to myself, ‘I can’t believe they pay me to do this.’ I just loved going to work and doing what I did.”  Post-retirement, he has focused his exceptional skills on the plant world, enabling people to see fruits and vegetables in a whole new way.  His image of trichomes on a cucumber received an honorable mention from the NSF’s International Science and Engineering Visualization Challenge in 2011.  Check out the image here.

As I transitioned to teaching, I realized that students often share this joy found by looking through the microscope lens.  This year, my school invested in a suite of Moticam 2300s.  My students can now get high resolution photographs with both our compound light microscopes and our stereo microscopes.  The images and video below are a few of my favorites that they captured this year.

Stamen of an Iris

Ovary of an Iris

Skeletal muscle

Simple cuboidal epithelium

A Question of Content

As we move towards the new AP Biology curriculum set to begin in the fall of 2012, the question of content is a big one.  Visit the Advances in AP web site, and you’ll find the following quote:

“Science is a way of thinking much more than it is a body of knowledge.”

– Carl Sagan

While I find the current curriculum to be excessive in its breadth, the notion that learning biology is exclusively about learning a set of skills does not sit comfortably with me either.  On one hand, I groan each year as I approach animal diversity, wondering when my students’ ability to differentiate among acoelomates, coelomate, and pseudocoelomates will come in handy in the future.  Thus, the decision to remove this detailed information from the curriculum led me to breathe a sigh of relief both for myself and for my future students.  However, when I read the new framework and saw that “memorization of the names of the phases of mitosis is beyond the scope of the course and the AP Exam,” I felt a little taken aback.  In my opinion, students could very well come across an article on cancer, and an understanding of the process of cell division would indeed be very useful to comprehend the article.  Furthermore, while virtually none of my students will go on to become comparative developmental biologists, a good portion are likely to work in the healthcare field, where knowledge of biology relating to cancer is pertinent.   Therefore, while I am grateful that the tightening of the curriculum will alleviate the panic that sets in when a snow day sets me back one day on my syllabus, I am not entirely comfortable with all of the changes to the AP Biology curriculum.

Reading Daniel Willingham’s book, Why Don’t Students Like School has helped me to better understand what is making me a little uncomfortable with the notion that science is all about skills.  He argues that background knowledge is essential for both reading comprehension and for critical thinking.  I find his argument entirely convincing.  I urge educators to dig into his book, but I will highlight a few points here.

With regards to reading comprehension, Willingham emphasizes the importance of background knowledge by asking his audience to read the following passage:

The procedure is actually quite simple.  First, you arrange items into different groups.  Of course one pile may be sufficient depending on how much there is to do.  If you have to go somewhere else due to lack of facilities, that is the next step; otherwise, you are pretty well set.  It is important not to overdo things.  That is, it is better to do too few things at once than too many.

To most, this passage is not easy to comprehend.  None of the vocabulary is difficult, but, as Willingham notes, it is “vague” and “ambiguous.”  However, had you first been told that the title of the passage is “Washing Clothes,” your comprehension would have been much better.  Willingham states that “we interpret new things we read in light of other information we already have on the topic.”  He notes that in the case of “Washing Clothes,” the title “tells the reader which background knowledge to use to understand the passage” (26-27).

For more on reading comprehension, you can also watch this:

Willingham makes a similar argument for critical thinking.   He challenges readers with the following problem involving cards with a person’s drink on one side of the card and their age on the opposite side.  Your task is to analyze the set card set below and enforce the rule that if you are drinking beer, then you must be twenty-one or over.  You must verify the rule is met for the card set below by turning over the minimum number of cards.

Many of us are familiar with this topic, and it is relatively straightforward to pick out the beer card and the 17 card as important for verification of the rule.  It doesn’t matter what a 31-year-old person is drinking.  Likewise, it is acceptable for anyone regardless of age to drink coke.  Interestingly, Willingham points out that when researchers give college students an analogous problem, except this time the task is to verify the rule that if there is a vowel on one side of the card, there must be an even number on the other side of the card, the students aren’t very successful.  Only 15-20 percent of college students figure out how to verify that rule for the following card set:

Why the discrepancy if the problems are so similar?  Part of it, Willingham argues, is that you bring experience, or background knowledge, to the first problem, making it easier to solve (29-30).

At a time when educators are urged to focus on skills, skills, skills, Willingham puts forth a convincing argument that knowledge is a vital piece in attaining the skills that we value, like reading comprehension and critical thinking.  He offers some practical advice to educators regarding content, with the realization that our textbooks are bursting at the seams with both relevant and not so relavent material.  So, what to teach?  Willingham argues that a “minimum target” is for students to graduate with the knowledge required “to read a daily newspaper and to read books written for the intelligent layman on serious topics such as science and politics.”  For core subjects, like math, science, and history, Willingham argues that it is necessary to teach what comes up “again and again” (36-37).

So what is the take away message for a biology teacher?

1.  For my general biology students, I want them to leave with enough background knowledge to be able to comprehend biology-related articles in the science section of a newspaper.

2.  For my AP students, I want to instill an enduring understanding of topics that they are likely to encounter again if they go on to more advanced biology classes in college.