Texas TEKS 7.12

7.12 is a TEKS knowledge and skills statement. These are the student expectations under it.

• 7.12.A

  diagram the flow of energy within trophic levels and describe how the available energy decreases in successive trophic levels in energy pyramids

• 7.12.B

  describe how ecosystems are sustained by the continuous flow of energy and the recycling of matter and nutrients within the biosphere.

01

What Students Need to Do

Students build and read energy pyramids that show producers and consumers at each feeding level. They use arrows to track energy transfer and explain why less energy reaches higher levels. They also distinguish one-way energy transfer from the reuse of matter by decomposers and other organisms.

02

What Mastery Looks Like

A student correctly places organisms in an energy pyramid and draws arrows in the direction energy moves. The student explains energy loss through heat and life processes. The student traces water, carbon, or nutrients from organisms back into the environment and into living things again.

03

Common Misconceptions

Students may point arrows toward the organism being eaten instead of toward the energy receiver. They may think top consumers have the most energy because they are at the top. They may also say energy is recycled, rather than recognizing that matter cycles while energy leaves as heat.

04

How to Assess It

Give students grass, rabbit, snake, and decomposer cards. Ask them to draw an energy pyramid, add arrows, explain the decrease in energy, and trace nutrients after the snake dies.

1. 01

   Give groups 1,000 beans as producer energy, then transfer 10 percent upward through cups labeled producer, primary consumer, and secondary consumer.

2. 02

   Ask students to write why a grassland can support many grass plants but only a few hawks, using energy loss as evidence.

3. 03

   Run a card-sort relay where teams arrange organism cards into energy pyramids, add arrows, and correct one hidden error.

4. 04

   Trace sunlight, vegetables, food scraps, compost, and soil nutrients through a school garden to compare energy transfer with matter recycling.

• 6.12

  Organisms and environments. The student knows that interdependence occurs between living systems and the environment. The student is expected to:

• 3.12

  Organisms and environments. The student describes patterns, cycles, systems, and relationships within environments. The student is expected to:

• 5.12

  Organisms and environments. The student describes patterns, cycles, systems, and relationships within environments. The student is expected to:

• 4.12

  Organisms and environments. The student describes patterns, cycles, systems, and relationships within environments. The student is expected to: