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Session 7. Energy Flow in Communities
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The sun, source
of energy for life on Earth |
Learning Goals
During this session, you will have an opportunity to
build understandings to help you:
- Distinguish between energy and matter as they relate to
the living world
- Distinguish between producers, consumers, and decomposers with
regard to energy flow in a community
- Describe what happens to energy as it moves through a community
Video Overview
In Session 1, we saw that one characteristic of life was the need
for a constant supply of matter and energy. Why is this? What’s
the difference between the two? The next two sessions explore these
questions. Session 7 focuses on energy and life, while Session 8 focuses
on matter and life.
Video Outline
One consequence of evolution is a living world that is both remarkably
diverse and incredibly complex. Session 7 begins a study of life
at the level of communities – where diversity and complexity
are sustained, in part, by the constant flow of energy. Thinking about
food chains in communities focuses us on the connection between
energy
and life.
Dr. Herbert Thier, representing the SCIS3+
curriculum,
highlights the importance of building understandings of community-level
phenomena
in the elementary school years. We see this happening in Melissa
Minnick’s
fifth-grade classroom in Walkersville, Maryland, where they are
using the SCIS3+ unit “Communities” to explore energy
flow along food chains in classroom terrariums. Throughout the
program, interviews
with fourth and fifth graders in the Science Studio reflect research
on children ’s ideas about energy and life.
Our own exploration
of energy flow begins with a distinction between energy and matter
and how both relate to food. We then proceed
to look at energy reactions along the links of a food chain. Dr.
Aaron Ellison, who researches carnivorous plants, looks at producers
and
examines photosynthesis as one key energy reaction, followed by
the introduction of cell respiration as another. Dr.
Marianne Farrington,
of The New England Aquarium, goes behind the scenes to highlight
the
consumers and their energy needs. Decomposers are next in line
as we visit a compost research facility, where Dr.
Sanat Majumder describes
their role in energy flow.
Dr. Les Kaufman, an ecologist, introduces
us to energy pyramids as he describes what happens to energy as
it flows through a community – setting
up what will ultimately be a distinction between energy and matter.
And Dr. Paul Williams returns, highlighting progress with Bottle
Biology and pointing out a system for studying energy flow: the EcoColumn. View the video ==>
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