Cells and Life Processes
Grade 7 | Science | Unit 04
Teacher's Guide
Learning objectives
- Explain the central ideas of cells and life processes using appropriate vocabulary.
- Apply the worked example and justify answers to the practice questions.
- Complete the investigation or design task and identify a limitation of its model or evidence.
Prerequisites: Basic reading, arithmetic, and observation skills.
Suggested time: Two or three 45-minute sessions; extend the activity when needed.
Teaching sequence
- Elicit a prior explanation of the topic and note uncertain vocabulary.
- Discuss the concept section, distinguishing observations, models, and assumptions.
- Work through the example. Ask students to explain each step and check any units.
- Complete the activity, then use the five practice questions as an individual check.
- Review the two vocabulary questions and revisit misconceptions revealed by the answers.
Assessment and differentiation
Use the seven questions in the companion CSV for retrieval practice or a short quiz. Award one point per entry for an accurate answer; accept scientifically equivalent wording. Treat five correct answers as a suggested checkpoint for further review, with both reasoning and activity quality assessed separately. Support students with a labeled diagram, a word bank, or a completed first step. Extend by asking students to change one example condition, predict the effect, and explain a limitation.
Student Worksheet
Concept and helping material
Living organisms are made of cells. Cells are the basic units of living structure and function, and new cells arise from existing cells. The cell membrane controls exchange with the surroundings. Cytoplasm contains the working components of the cell; DNA stores inherited instructions. Eukaryotic cells contain a nucleus, while prokaryotic cells do not. Plant cells usually have a cell wall, a large central vacuole, and chloroplasts in photosynthetic tissues. Diffusion moves particles down a concentration gradient; osmosis is the movement of water across a selectively permeable membrane.
Vocabulary
- Cell membrane: A selectively permeable boundary surrounding a cell.
- Osmosis: Net movement of water across a selectively permeable membrane.
Worked example
If there is a higher concentration of a dissolved substance on one side of a permeable membrane, net diffusion moves that substance toward the lower concentration. Particles still move in both directions.
Investigation or design task
Draw and label a generalized plant cell and animal cell. Use arrows to model net diffusion. State why your drawing is a simplified model.
Practice
- What three ideas form cell theory?
- Which structure contains DNA in a typical eukaryotic cell?
- Name a structure in plant cells that animal cells lack.
- In which direction does net diffusion occur?
- Do bacteria have a membrane-bound nucleus?
Vocabulary retrieval
- Define Cell membrane.
- Define Osmosis.
Reflection
Explain which evidence, calculation, or model supports one of your answers. State a condition under which your explanation might need revision.
Answer Key
- Organisms consist of cells; cells are the basic units of life; cells arise from existing cells.
- The nucleus.
- A cell wall; chloroplasts are another example in photosynthetic plant cells.
- From higher concentration toward lower concentration.
- No. Bacteria are prokaryotic cells.
Vocabulary definitions appear above and are also included in the CSV. Activity answers may vary; require a clear method or design, correct use of lesson concepts, and an explicit limitation. Reflection is assessed for reasoning rather than one fixed phrase.
Source Reference
Everything You Need to Ace Science in One Big Fat Notebook, PDF viewer pages 303-344 (1-based). Page numbers refer to this supplied file and may differ from printed page numbers. The source is background reading for the grouped topic. Lesson explanations, examples, and questions are original teaching material; they do not reproduce the book's worksheets or illustrations.