bio-sequence

[Martha Phillips]

I've been following the "bio-sequence" discussion and really enjoying what 
people have to say and I'd like to add my two cents worth to the discussion: 

Our department has gone through some serious curriculum development and change,
especially in our introductory sequence, over the past 6 to 7 years.  I have 
been here 4 years, and so came on in the middle of it.  The gist of what we have
done in our 2 semester General Biology sequence is to change to a theme-based 
approach, with the idea that if what the students are learning is related more 
directly to them, to their lives and to their interests, then they will learn it
better and retain more.  In addition, we have switched to a 2 lectures/1 small
group discussion format (with all 7 members of the department taking part in 
being a discussion group leader).  We have also changed the lab so that we no 
longer do any cookbook exercises and each semester the students work in groups 
to do semester-long research projects of their own design -- the focus of lab is
the process of science, not the content.

I teach at a Catholic women's college (the College of St. Catherine in St. Paul,
Minnesota).  The first semester is the "Biology of Women" (which obviously works
since this it a women's college -- it could be the "Biology of Humans" in a coed
institution).  Within the context of topics such as the menstrual cycle, 
reproduction (and the control of reproduction), genetics and sex, cancer, 
nutrition, etc. they learn some basic anatomy and physiology, biochemistry, cell
biology, genetics, and microbiology.  The approach used is to introduce a topic 
that should be of interest, and then teach the basics that are needed to 
understand that topic.  The course ends up taking more of a micro to macro 
approach, but not in a strictly linear fashion.  

I teach the second semester, which is taught around the theme of "Environmental 
Interactions and the Strategies of Life."  (Kind of a mouthful, but I haven't 
come up with a quick title that really says it all.)  Basically, I cover the 
topics of plant biology, ecological principles and evolution -- with an attempt 
to incorporate environmental issues of interest to the students.  But I don't 
take the linear (and I think more boring) approach of teaching all about plants,
then ecology, and then evolution.  I interweave the main principles of these 
disciplines through a discussion of the things that all living things need to 
live and persist.  (Hopefully I make some good connections to their lives and 
interests in environmental issues, but it's a bit of a hard sell --most college 
freshmen think plants are stupid, ecology is picking up cans and you have to be 
an atheist to believe in evolution).  I do cover a bit of animal biology, 
especially to make the point that the basic physical, chemical, physiological, 
and evolutionary principles governing plants and animals are the same. My flow 
of topics is listed below.  As you'll see, it's not strictly micro to macro, or
the other way around.  

Unit 1:  The Acquisition and Transfer of Food
	  Taxonomy and the Kingdoms of Life  
		    (as they are based largely on modes of nutrition)
	  Photoautotrophism:  Photosynthesis  (2 lectures)
	  Photoautotrophs in More Detail:  
		   Transport in Plants  (2 lectures)
			   (I start with just enough plant anatomy for them to understand
 				  transport)
		   Plant Mineral Nutrition and Soils
			    (bringing up soil conservation, sustainable agriculture, etc.)
	  Nutrition of Ecosystems:  Energy Flow and Nutrient Cycling (2 lectures)
		  	(includes a discussion of the "Greenhouse Effect")

Unit 2:  Living in and Responding to the Abiotic Environment
	  Distribution and Adaptations of Organisms  
		  (includes discussion of major abiotic factors, climate, biomes)
	  Homeostasis and Water Balance 
		  (I cover both stomatal regulation and kidneys)
	  Temperature and Thermoregulation  (more animal than plant focus)
	  Sensing and Responding to the Abiotic Environment  (2 lectures)
		  (I contrast plants and animals in how they sense, internally communicate and
    respond, but cover plant responses mainly.  This includes tropisms, turgor 
  		responses and a little bit of plant hormones.  If there's time I may 
    contrast	plant reception of light with the mammalian eye)

Unit 3:  The Biotic Environment
  	Biotic Interactions
	  Community Structure and Change
	  Effects of Human Disturbance
		  (I focus on exotic species and loss of biodiversity)

Unit 4:  Reproduction, Dispersal and Growth
  	Life Cycles and the Diversity of Plants
	  Reproduction and Dispersal in Angiosperms
	  Reproductive Strategies  (both plant and animal)
	  The Growth of Individuals:  Growth in Angiosperms
	  The Growth of Populations  (including a discussion of human popn growth)

Unit 5:  Evolution:  A Population Response
  	The Darwinian Revolution
	  Evidence of the Fact of Evolution
	  Mechanisms of Evolution:  The Theory of Evolution
 	 Natural Selection:  The Only Mechanism of Adaptive Evolution
	  The Origin of Species:  Speciation
	  Issues and Misconceptions in Evolution

Some students get annoyed that we skip around in the book (this year we are 
using Campbell) and that the material is not presented in a strictly linear 
fashion.  I'm not convinced, however, that they would understand and retain it 
any better if we did just plow through chapter 1, then 2, etc.  I certainly 
enjoy it much better teaching it this way.  I agree with the comment that if the
order (whatever it is) suits YOU, then both you and the students will have an 
easier time of it and it can be very successful.  

Each time I teach the course I cut out more content.  There is so much that we 
can expose them to, but does it really work to do that?   I am sometimes 
dismayed at how little they seemed to retain into later years -- having just 
finished teaching botany to a group of students that I had in General Biology. 
I am always looking for what are the key things that will stay with them -- and 
what are the concepts that connect many disciplines in biology?    I think, for 
example, that in terms of transport in plants, it is more important that they 
come away from general biology with a very good understanding of diffusion, 
osmosis, membrane transport and electrochemical gradients than that they recall 
the difference between tracheids and vessel elements.   It's not that I won't 
discuss the structure of xylem, but I'm going to hit the other stuff harder.  
 

I'd be interested in hearing more about what people think are main concepts 
within each major topic that they think a student in an introductory course 
should be exposed to -- such as, do most of you go through the chemiosmotic 
theory of ATP synthesis when teaching photosynthesis or cellular respiration, or
do you "black box" ATP synthesis and wait until an upper level course to go into
detail about the mechanism?  What are the thoughts on that type of issue?


Martha Phillips
Department of Biology
College of St. Catherine
2004 Randolph Avenue
St. Paul, MN 55105
(612)690-6630
mmphillips at alex.stkate.edu