Middle School

Ecosystems and Energy Flow

Photosynthesis, cellular respiration, food molecules, energy flow, and matter cycling.

MS-LS1-6, MS-LS1-7, MS-LS2-3 2 lessons 4 quiz questions

Lesson 1: Photosynthesis and Respiration

Trace matter and energy through life processes.

Learning goals

  • Explain photosynthesis.
  • Explain cellular respiration.
  • Compare inputs and outputs of both processes.

Photosynthesis

Plants, algae, and some microorganisms use light energy to make sugars from carbon dioxide and water. Oxygen is released as a product.

Cellular respiration

Cells use food molecules and oxygen to release energy for life processes. Carbon dioxide and water are products.

Lesson 2: Energy Flow and Matter Cycling

Model food webs and cycles in ecosystems.

Learning goals

  • Describe energy flow in food webs.
  • Explain matter cycling.
  • Identify producers, consumers, and decomposers.

Energy flow

Energy enters most ecosystems as sunlight and flows through producers, consumers, and decomposers. Some energy is transferred as heat at each step.

Matter cycles

Matter cycles between organisms and the nonliving environment through feeding, waste, death, decomposition, air, water, and soil.