This must be a widespread dilemma, certainly one that I have faced, too. I
starting off thinking that beginning with the whole organism, the
angioserm, would be the most appealing to students. I am not sure now, and
I think that the root is the fact that the biology that most high-school
kids get is molecular and cell biology, not organismal or evolutionary
biology. They simply are not used to thinking about what it really means
to say that 'cells are the building blocks of life' or some such.
The quiz I give them on the first day of class illustrates this very
nicely; however, even here there are problems: a surprising fraction think
that plants have no mitochondria. Of course, this partly may be due to the
types of students who take my course on Plant Diversity (lecture-lab):
mostly aspiring medicos fulfiling a lab need for an organism-level course
and a smattering of aspiring environmental biologists.
It is the second group of students that like the historical approach
because, I think, they have some familiarity with flowering plants, the
'ultimate stage.' I think students who do not have this familiarity just
don't like the open-endedness of such an approach; they want to know where
it is all going (if, that is, they think of it other than in terms of
what-do-I-need-to-do-to-get-an-A-in-this-course).
One way might be to give them a sense of the range of cell types at the
start, but without going into the details of tissue types and
organization. This year I thought I'd introduce them, in lab, to the types
of cells in one of two ways:
1) use the range of organisms that we would be looking at during the
course of the semester: parenchyma in Marchantia, sclerenchyma, tracheids
in Psilotum etc.
2) use vegetables & fruits to introduce different types of cells and
tissues.
I haven't quite made up my mind about which way to go; I'm sure there is
something to be said for both. I like the first one because it would, in a
sense, lay out the whole course for them so they will know where it is
going, if they are paying attention to the organims at the same time.
I use Raven et al., too, but it is not ideal...
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Geeta Bharathan
Assistant Professor
Department of Ecology and Evolution
State University of New York
Stony Brook, NY 11794-5245
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