Digestive System Start

Overview

This lesson introduces the digestive system as a body system that breaks down food and provides nutrients and energy. Students begin a 24-lesson unit by brainstorming prior knowledge, learning key terminology, and using simple diagrams to connect structure to function in later lessons.

Learning intentions

• Students will explain why digestion is important for energy, growth, and repair.
• Students will identify major parts of the human digestive system (at least: mouth, oesophagus, stomach, small intestine, large intestine).
• Students will use key digestive-system terms accurately in short explanations.
• Students will begin a personal glossary for the unit and record one learning fact at the end.

Success criteria

• I can describe the purpose of the digestive system in my own words.
• I can name major digestive system parts and state a simple function for each.
• I can use at least four correct key terms from today in a short sentence.
• I can write one accurate fact learned today in the exit ticket.

Curriculum links

• Biological science: Digestion — Identifying parts of the human digestive system and explaining their functions.
• Biological science: Digestion — Tracking the pathway of food through the digestive system using diagrams or physical representations and explaining how structures and functions work together.
• Biological science: Body systems / Digestion — Animals’ digestive systems break down food and absorb nutrients for fuel and growth.
• Key competencies: Thinking (making sense of ideas and connections), Relating to others (group discussion), Using language/symbols (scientific terminology and diagram labelling).

Lesson structure (55 minutes)

1. 0–5 min · Do Now activity: Mix and match (Slide). Teacher presents a slide with a mix and match exercise where students match parts of the digestive system (mouth, oesophagus, stomach, small intestine, large intestine) to their functions (break down, move food, mix/churn, absorb nutrients, reabsorb water). Students complete individually or in pairs.

2. 5–15 min · Quick class share and misconceptions. Teacher records student ideas on the board under two headings: “What we think happens” and “Questions we have”. Students identify one idea they agree with and one question they want answered in the unit.

3. 15–25 min · Direct teach: digestion purpose. Teacher gives a short explanation: digestion breaks down food into smaller substances so the body can use nutrients for fuel, growth, and repair; absorption happens in the intestines. Students sketch a simple “food goes in → body uses nutrients” flow on a page and add any new terms they hear.

4. 25–30 min · Terminology and pathway introduction (Slide with worksheet questions). Teacher displays a slide with key digestive system terms and asks interactive questions from the worksheet to check understanding. Provide sentence starters to support student responses, such as: "The ___ is important because...", "I think the function of ___ is...", or "___ helps by...".

5. 30–40 min · Terminology and pathway (teacher model + guided practice). Teacher displays a basic, labelled digestive-system diagram (mouth to large intestine) and models how to trace the path with a finger while saying each part. Students label a blank version with the five required parts and write a single-word function beside each (e.g., mouth—break down; stomach—mix/churn; small intestine—absorb; large intestine—reabsorb water/solidify; oesophagus—moves food).

6. 40–45 min · Structure–function reasoning in groups (Worksheet questions integrated). Teacher sets groups of three to discuss: “Choose two parts and explain how the part’s structure helps its job.” Students use sentence starters on the worksheet: “The ___ helps because ___.” Aim for structure-language at Year 9 level (e.g., folds/walls, length, movement/muscle action), even if explanations are simple.

7. 45–52 min · Mini-checks (teacher circulates + class check with interactive questions). Teacher circulates to listen for correct terminology and accurate functions; addresses common errors (for example, confusing digestion with breathing, or claiming the stomach absorbs all nutrients). Students revise one label/function on their diagram after feedback. Teacher uses interactive question slides from the worksheet to assess understanding. Sentence starters such as "I think ___ because..." or "The function of ___ is..." can be encouraged here.

8. 52–55 min · Exit ticket (individual) (Slide). Teacher explains: “Complete the cloze activity: ‘The ___ breaks down food, and the ___ absorbs nutrients.’ Write one fact you learned today.” Students submit on a slip: one sentence with at least one key term correctly used.

Resources

• Printed starter diagram with blank labels (mouth, oesophagus, stomach, small intestine, large intestine)
• Small-group worksheet with sentence starters, two-part explanation prompt, and interactive question slides
• Unit glossary template (space for term + definition + one example sentence)
• Board/marker or digital board
• Exit ticket slips or a digital form (teacher chooses)
• Timer for each activity segment

Assessment

• Formative: teacher listens during partner sharing and group discussion; notes misconceptions in a quick checklist.
• Formative: diagram labelling and one-word functions show whether students can connect parts to functions.
• Summative-lite for this lesson: exit ticket—one accurate fact learned today with at least one key term.

Differentiation

• Support: provide a word bank on the worksheet (mouth, oesophagus, stomach, small intestine, large intestine; break down, move, mix/churn, absorb, reabsorb water) and sentence starters for explanations.
• Support for language learners: allow students to write definitions in a first draft using simplified wording, then add one scientifically accurate term.
• Extension: challenge groups to add one additional digestive structure (e.g., liver, pancreas, rectum) and write a function link; or explain “why the small intestine is long” using structure–function reasoning.
• SEN considerations: allow diagram labelling with reduced writing (function can be a short phrase or one key word) and provide a peer model for tracing the pathway.

Exit ticket prompt (teacher-ready)

• “Write one fact you learned today about the digestive system.”
• Include one key term from your diagram and one correct function.