digitat & Brassica rapa: |
University Comes to Marcus Whitman!
Whitman Central School District Newsletter. April 2002.
Whats a great way
for kids to learn biological concepts, using a hands-on approach?
How about growing some plants and insects??!!
Since the beginning of
classes in September, Rebecca
Smyth, an entomologist from Cornell Universitys school
of Agriculture & Life Sciences, has been visiting Pete Saracinos
7th and 8th grade Biology classes. Ms. Smyth is a PhD. candidate
and a Fellow with the Cornell Environmental Inquiry Research Partnership
(CEIRP). The Partnership provides support for teachers and students
conducting original research or inquiry-based projects in the environmental
sciences. Cornell undergraduate and graduate Fellows guide classroom
projects using Environmental-Inquiry curricula as well as activities
the fellows develop based on their own research expertise.
Each Friday since early
September has been Cornell Day in Mr. Saracinos
Biology classes. Relying on Rebeccas expertise, Mr. Saracinos
classes have been engaged in two different studies. One study involves
raising parasitic wasps, scientific name: Melittobia
digitata. Dont worry. These wasps arent much larger
than a flea. And they dont sting! The other involves raising
mustard plants, scientific name: brassica rapa.
So, why on Earth would
anyone want to raise wasps??!!!
The answers easy!
What better way to explore a good number of Life Science concepts
than to raise a little life!! Principles like life
cycles (each student raised the wasps from adult to egg to larva
to pupa and back to adult), metamorphosis (students were able to
see each life-stage first-hand), symbiosis (adult female wasps
are parasitic on mud daubers; they lay their eggs on mud dauber
pupae; once hatched, the larvae use the pupae as a source of nourishment),
reproduction (students used bioassays to study how the female wasps
find a sexual partner using chemical cues called pheromones), parthenogenesis
(if the female wasp cannot find a male to mate with, she simply
lays more eggs; the eggs that hatch are all males, and she mates
with her own offspring!) come easily to life as the kids see the
action taking place before their very eyes. And students had their
own batch of wasps to observe and study! Another bonus of this
project was the skill gained by the students in using a dissecting
microscope. These wasps are very small, and the kids were often
required to observe the action under these microscopes.
In the end, they became quite proficient at operating these scopes.
Last, but not least, the students were required to keep a lab manual
where daily observations were recorded and drawings made. This
gave them practice doing science just like real scientists do!.
Now, on to mustards!
What can be learned from this humble plant? The answer is natural
selection and genetics! What better way for kids to learn about
these concepts than by growing plants, observing their traits,
then choosing (or selecting) which traits they want
to try to pass along to potential offspring?
guidance thats exactly what the kids did. They grew the mustard
plants from seeds. Care was taken to ensure that each plant was
given the same conditions of light, temperature, fertilizer, and
moisture. As the plants grew, students made careful observations
- complete with drawings of each phase of the plants
life just like real scientists.
Why such meticulous care
and observation? The goal of this phase of the project was to determine
if certain traits were heritable. That is, would a
tall plant be able to pass along its trait for tallness
to its offspring? Or, was a plants height determined only
by the conditions in which it grew? Or, perhaps the trait reflected
a combination of both heredity and environment!
The two traits chosen
were height and degree of stem hairiness.
These traits were measured on each plant. Then, pipe cleaners in
hand, the students pollinated flowers. Tall plants were crossed
with tall plants; short were crossed with short; hairy were crossed
with hairy; smooth were crossed with smooth.
And then, they waited.
The plants were allowed
to go to seed. These seeds were then harvested and used by the
kids to grow the next generation of plants. When the new generation
had grown to their full stature, new measurements were taken, results
tabulated, and conclusions drawn.
Much was learned! By
growing, observing, drawing, pollinating, harvesting and replanting
real-life plants, the kids received first-hand knowledge about
plant and flower parts, plant pollination and reproduction, seed
harvesting and replanting, genetics and natural selection.
In closing, both projects
provided Whitman students with an avenue to learn a broad range
of biological concepts. A more subtle benefit to the kids was the
opportunity to work with a real-life scientist and a female
one at that! Ms. Smyth provided the students with an excellent
role model for young people especially the young girls -
who aspire to pursue a career in the sciences.
The projects were a great success.
Mr. Saracino feels that they were so beneficial he has decided to have a Cornell
fellow join his classes each fall to help Whitman students explore the world
here to see photos.