Activity 3: Teaching Tips
The blank data table is available as Blackline Master Ecology 3.1: Energy Flow Data.
You may wish to supplement this activity with the dramatization suggested
in Learning Strategies for Students with Limited English Proficiency.
You may wish to supplement this activity with the dramatization suggested
in Learning Strategies for Students with Limited English Proficiency.
You may wish to use the Assessment Rubric for Graphs to assess the students’ graphs. This rubric is available in the Teacher’s Edition at the end of this activity.
The illustration on student page 524 is available
as Blackline Master Ecology 3.2: Pyramid of Energy.
In 1977 geologists were exploring fractures in the ocean floor. Located deep
in the ocean, they found thermal vents surrounded by a very unusual ecosystem. The vents spew out hydrogen sulfide. No one would have expected to find life around these vents. The water here is frigid, except near the vents, were it is incredibly hot–hundreds of degrees Celsius. No sunlight can penetrate that
deep into the water, so there are no plants because they need sunlight to
photosynthesize. The scientists were amazed to discover large tube worms,
almost a meter in length. These worms had no mouths or digestive systems.
They also found white crabs that were blind.
They discovered that the producers in this food chain were chemosynthetic
bacteria. These bacteria used chemical energy in the hydrogen sulfide gas
to make their food. The other organisms in this ecosystem ate the bacteria,
harbored bacteria in their bodies, or ate the bacteria eaters.
Students may wonder why the numbers in the text do not match the numbers in the diagram. Point out that the text talks about supporting 1 kg of human mass, where as the diagram represents the living matter required to support a person with a mass of 100 kg.
Note that the diagram is not really drawn to scale. You may wish to ask students to draw a diagram to scale to illustrate the tremendous size of the producer box, compared to the top consumer.
You may provide the students with the following questions to assess their understanding of the reading:
1. What is the source of energy that enters the food chain?
(The Sun)
2. What limits the size of a community?
(The energy provided by the producers)
3. State the first and second laws of thermodynamics.
(The first law states that although energy can be transformed,
it cannot be created or destroyed. The second law states that
in any energy transformation, some energy is lost from the system
in an unusable form.)
4. What form does the unusable energy lost from a system usually take?
(Heat)
5. What is a trophic level?
(Energy level) |