Middle school (6–8)
Science
Science: Cells & Organisms: Easy Practice
Free middle school life science practice on cells and organisms. Students review cell theory, organelle functions, and how cells form tissues, organs, and systems. Build confidence with foundational questions. Review key vocabulary and core skills before moving to harder sets.
Easy Level Guide
Build confidence with foundational questions. Review key vocabulary and core skills before moving to harder sets.
Cell Theory
All living things are made of cells. Cells are the basic unit of life. New cells come from existing cells. Cells may be prokaryotic (no nucleus) or eukaryotic (with a nucleus and membrane-bound organelles).
Plant and Animal Cells
Both have a nucleus, mitochondria, ribosomes, and a cell membrane. Plant cells also have a rigid cell wall and chloroplasts for photosynthesis. Large central vacuoles store water in plant cells.
Organelle Functions
The nucleus controls cell activities and stores DNA. Mitochondria produce energy (ATP). Ribosomes build proteins. The endoplasmic reticulum and Golgi apparatus process and ship materials. Lysosomes break down waste.
Levels of Organization
Cells form tissues, tissues form organs, organs form systems, and systems form organisms. Each level has emergent properties. Unicellular organisms carry out all life functions in one cell.
FAQ
- Are prokaryotes covered?
- Cell theory mentions prokaryotes and eukaryotes, with emphasis on eukaryotic plant and animal cells.
- Does this connect to human body systems?
- Yes. The levels of organization section bridges cell biology to organs and systems taught in grade 7 and 8.