Photosynthesis and cellular respiration are the two connected processes at the heart of this Grade 8 science worksheet. Students investigate how plants capture light energy, store it in glucose, and release usable energy through cellular respiration. They also examine a key distinction in ecosystem science: matter cycles between organisms and their surroundings, while energy flows through living systems and is eventually dispersed as heat.

The reading passage explains how photosynthesis occurs mainly in chloroplasts, using carbon dioxide from the air and water absorbed by roots to produce glucose and oxygen. Cellular respiration takes place in plant and animal cells, using glucose and oxygen to release usable energy. Students encounter ATP as a molecule that powers cellular activities and consider why plants need respiration even when sunlight is unavailable.

Connect cell processes to matter and energy

Rather than treating photosynthesis and respiration as interchangeable processes, students compare their different roles. Photosynthesis stores light energy as chemical energy in glucose, while cellular respiration transfers energy into forms cells can use. The resource also traces carbon atoms from atmospheric carbon dioxide into glucose and explains how respiration can return carbon to the environment.

These examples give learners a foundation for explaining biological processes with scientific evidence. They must distinguish raw materials from products, identify where photosynthesis mainly occurs, and use the relationship between glucose, oxygen, carbon dioxide, water and ATP to support their reasoning.

What the worksheet asks students to do

• Multiple-choice questions assess the inputs and outputs of photosynthesis and respiration, chloroplasts, ATP, plant respiration in darkness, and the movement of carbon through living systems.
• True-or-false questions check understanding of energy storage, respiration, process differences and energy transfer through ecosystems.
• Short-answer questions ask students to explain why plants need both processes, trace carbon from the air and challenge the claim that plants stop releasing usable energy after sunset.
• A labelled diagram, categorizing activity and short note provide further opportunities to organize biological information and communicate scientific ideas.

Files and teacher support included

• The student worksheet with a reading passage and process-focused activities.
• A separate PDF answer key for checking responses.
• Student Notes lines at the bottom of the worksheet.
• A Teacher Guide within the answer key PDF, including Learning Objectives, Teaching Tips, Discussion Questions and Common Mistakes.

Practical classroom applications

Use this photosynthesis and cellular respiration resource when teaching Grade 8 cells and life processes, reviewing how plants obtain and use energy, or assessing students' explanations of matter cycling and energy flow. It can support a lesson follow-up, independent written practice or a review before moving to more complex ecosystem concepts.

The combination of a reading passage and questions that require students to explain, compare and trace processes helps reveal whether they can connect individual cell reactions to larger biological systems. The separate answer key and embedded teacher guide provide support for checking work and addressing common misunderstandings, including the idea that plants respire only in daylight or that matter and energy move through ecosystems in the same way.