CELL FUNCTIONS
As the basic units of life, cells have needs and functions that are very
similar to those of whole organisms. Students' understanding of the functions
of cells develops along three major strands of benchmarks: the basic needs
of organisms, the basic functions that are performed in organisms, and
the structure of organisms and cells.
These strands of benchmarks first come together in middle school, where
the benchmarks include the idea that the basic functions of organisms
are carried out in cells. Later, when students know something about the
structure of matter, they can understand the synthesis of protein molecules
and the interactions of molecules within and between cells. This map has
some important relationships to topics that will be mapped in the next
edition of Atlas, including basic human functions and the commonalties
evident within the diversity of life.
Notes
Almost all of the benchmarks in this map come together in the 6-8 benchmark
"Within cells...," which lists the basic functions of cells. Similar functions
are described in the Flow of Matter in Ecosystems
map and the Flow of Energy in Ecosystems map on a
macroscopic scale. In addition, the similarity of cell functions in all organisms
is included in the Biological Evolution map, where
it provides evidence for descent from common ancestors.
In 9-12, ideas about the functions common to all cells are further extended
to the benchmark that different parts of the cell carry out specialized functions
and eventually that the proteins made in the cell carry out its work.
Extremely important contributions to achieving benchmarks about cell function
come from knowledge of the effect of the configuration of atoms in molecules,
conditions that affect reaction rates, and catalysts. Two benchmarks from
the Chemical Reactions map (in Chapter 4) appear
here to support the 9-12 benchmarks.
| Research in Benchmarks
Preliminary research indicates that it may be easier for students
to understand that the cell is the basic unit of structure (which
they can observe) than that the cell is the basic unit of function
(which has to be inferred from experiments) (Dreyfus & Jungwirth,
1989). Research also shows that high-school students may hold
various misconceptions about cells after traditional instruction
(Dreyfus & Jungwirth, 1988). |
