Bulldog News
Exploring an unseen world
Thursday, May 21, 2009
In what was described as a “mini-field trip,” members of teacher Sharon McKenna’s seventh grade science class recently ventured into the hidden world of microorganisms near the Hillside School campus.
Climbing aboard one of the school’s mini-buses, the students were transported to a section of the Assabet River shoreline to collect two different types of water samples.
As McKenna explained, the eventual goal of the trip was to “discover what kinds of microorganisms live in fresh and stagnant water” and, subsequently, “discern the similarities and differences between these forms of life.”
Fortunately, the weather was cooperative as McKenna and her students made their way to the edge of the Assabet on a warm April day.
Several students then tied ropes to buckets which were tossed into the river’s rushing waters to collect samples. Bottles were dipped into the buckets to scoop out what was, hopefully, water teeming with creatures unseen to the human eye.
Subsequently, the class made its way to a section of the river bordering Robin Hill Road where the water was still. Two students, Chris Coughlin ’11 and Gregory Mansfield ’11, volunteered to make their way through thick brush to obtain the necessary water samples.
The following Monday, the students gathered around classroom microscopes to determine the results of their efforts. Each student placed a drop from both the stagnant and fresh water samples on glass slides and then began their studies.
“Try looking with the microscopes on both low and high power,” explained McKenna, “then draw what you see and describe it in writing.”
Nearly all of the students were able to discern at least one microorganism within their droplets. Caleb Gillett ’11, for instance, caught sight of a one-celled creature from his fresh water sample which he described as “oval and moving back and forth.”
As students peered through the lens of their microscopes, exclamations of “that’s cool!” and “I see something!” could be heard throughout the classroom.
Ethan B. '11 came up with red bacteria with elaborate tendrils. “That’s a decomposer,” explained McKenna. “It consumes dead leaves and other matter.”
Matt Graham ’11 seemed to hit the jackpot with his sighting of two especially active microorganisms. One he described as “a sausage-like thing that was spinning” and another he depicted in his journal as “bat-like and moving in circles.”
“That is so cool!” Graham exclaimed while peering into his microscope at his miniature menagerie.
“The sausage-like thing was probably a rotifer,” surmised McKenna, “it’s a one-celled organism that is commonly found in still waters, including birdbaths.” She also suspected that several hydra – another common one-celled animal – were also viewed by the students.
“They came up with a lot from their research,” said McKenna following the class. “I’m sure we’ll have some fun identifying their findings.”
Matt Graham '11 celebrates his research finding.
Michael Oh '11 prepares a lab slide for viewing under his microscope.
