Matter Cycling in Organisms gives Grade 7 science students focused practice with how atoms are rearranged, conserved, and transferred through organisms. The resource connects digestion, biosynthesis, cellular respiration, carbon cycling, nitrogen cycling, and decomposers within the NGSS lesson topic From Molecules to Organisms: Structures and Processes.

What Students Explore

Students examine how digestion breaks food molecules into smaller molecules that can be absorbed, then trace how atoms from nutrients become part of cellular materials. The resource develops understanding of biosynthesis as cells rearrange atoms to build proteins, carbohydrates, lipids, and nucleic acids. Students also trace carbon as cellular molecules are used for energy and carbon dioxide is released during respiration.

Attention is also given to nitrogen cycling within organisms. Students identify how nitrogen atoms from food can become part of proteins and other molecules, how nitrogen can leave an organism as nitrogenous waste, and how decomposers return matter to the environment. Throughout the resource, students apply the idea that matter changes form while atoms remain present.

Practice That Builds the Concept

The worksheet combines a content-rich reading passage with multiple-choice questions, true-or-false statements, short-answer responses, a labeled diagram, a categorization activity, and a short note task. Questions ask students to explain digestion, identify biosynthesis, describe conservation of matter, trace carbon and nitrogen pathways, recognize the role of decomposers, and explain how respiration releases carbon dioxide.

Teacher-Ready Support

The separate answer key PDF provides answer support and includes a Teacher Guide with Learning Objectives, Teaching Tips, Discussion Questions, and Common Mistakes. Student Notes lines are also provided at the bottom of the worksheet, giving students space to record important ideas or reminders.

Classroom Use

Use this Grade 7 science worksheet for direct instruction follow-up, independent practice, concept review, formative assessment, or discussion preparation. The combination of selected-response and constructed-response tasks gives students opportunities to recognize accurate statements about matter cycling and explain the processes in their own words.

This resource is especially useful when teaching the movement and conservation of matter within organisms, including the relationships among digestion, biosynthesis, respiration, carbon, nitrogen, cellular materials, wastes, and decomposers.