Human Body: Digestion and Teeth

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Enquiry questions

How does the digestive system work, and what are the different types of teeth for?

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Concepts

This study delivers 1 primary concept and 3 secondary concepts.

Primary concept: Animal Nutrition (SC-KS2-C017)

Type: Knowledge | Teaching weight: 3/6

Understanding that animals, including humans, require the right types and amounts of nutrition and cannot make their own food — they obtain nutrition from what they eat. Contrasts with plants which can make their own food.

Teaching guidance: Explore the concept that animals, unlike plants, cannot make their own food and must eat other organisms. Classify foods into food groups (carbohydrates, proteins, fats, vitamins, minerals, fibre, water) and discuss the role of each in the body. Compare the diets of different animals and relate diet to body structure and habitat. Use food packaging labels to identify nutrients. Emphasise the contrast with plants — animals are consumers, plants are producers. Link to the concept of a balanced diet and why variety matters for health. Key vocabulary: nutrition, nutrient, carbohydrate, protein, fat, vitamin, mineral, fibre, balanced diet, food group, energy, consumer, producer, diet, health Common misconceptions: Pupils often think 'nutrition' means only eating healthy food, rather than understanding it as the process of obtaining the substances needed for growth and energy. Some children believe that fat and carbohydrates are always 'bad' rather than essential in appropriate amounts. Children may not understand the fundamental difference between plant and animal nutrition — that plants make their food while animals must consume it.

Differentiation

Model response (Entry): Animals need to eat to get energy to move and grow. A rabbit eats grass and plants. A fox eats other animals like rabbits.

Model response (Developing): Plants make their own food using light (photosynthesis), but animals cannot do this. Animals must eat other living things — either plants or other animals. Humans need carbohydrates for energy, protein for growth and repair, fats for energy and insulation, vitamins and minerals to stay healthy, fibre for digestion, and water.

Model response (Expected): Protein is needed for growth and repair — it builds and repairs muscles, skin and organs. Carbohydrates provide energy for activity and body functions. Vitamins keep us healthy — for example, vitamin C helps our immune system fight infections, and vitamin D helps our bones absorb calcium. An unbalanced diet causes problems: too little protein leads to poor growth, too few carbohydrates causes tiredness, lack of vitamin C can cause scurvy. A balanced diet means eating the right proportions from each food group, not too much or too little of any one type.

Model response (Greater Depth): A cow has flat, broad molars for grinding tough plant material and a very long digestive system with multiple stomach chambers to break down cellulose (plant fibre), which is hard to digest. A cat has sharp canine teeth and carnassial teeth for tearing meat, and a shorter digestive system because meat is easier to digest than plant material. The cow's long gut is needed because plants take more processing to extract nutrients. The cat's sharp teeth are needed to kill prey and cut through flesh. Each animal's body is adapted to efficiently obtain nutrients from its specific food source — structure matches function.

Secondary concept: Digestive System (SC-KS2-C031)

Type: Knowledge | Teaching weight: 3/6

Understanding the functions of the basic parts of the human digestive system: mouth (chewing, saliva), oesophagus (transport), stomach (churning, digestion), small intestine (nutrient absorption), large intestine (water absorption). Food is broken down to release nutrients.

Differentiation

Secondary concept: Types and Functions of Teeth (SC-KS2-C032)

Type: Knowledge | Teaching weight: 3/6

Understanding that humans have different types of teeth with different functions: incisors (cutting), canines (tearing), premolars and molars (grinding). Diet of carnivores and herbivores relates to different tooth structures.

Differentiation

Secondary concept: Food Chains with Producers, Predators and Prey (SC-KS2-C033)

Type: Knowledge | Teaching weight: 3/6

Constructing and interpreting food chains that include producers (plants), consumers, predators and prey. Understanding that food chains show the flow of energy and that producers are always the starting point. Extends KS1 simple food chains.

Differentiation

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Thinking lens: Systems and System Models (primary)

Key question: What are the parts of this system, how do they interact, and what happens when something changes? Why this lens fits: Bodily systems (circulatory, digestive, skeletal) are interacting systems; tracing inputs, outputs and feedback between them deepens the structural understanding. Question stems for KS2:

What goes into this system, and what comes out?

If you changed this one part, what else would be affected?

Where does this system start and end?

How could we draw a model to explain how this works?

Secondary lens: Structure and Function — Body parts, organs and systems are understood by connecting their physical structure to their biological function — why is the heart shaped as it is, and how does that shape enable pumping?

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Session structure: Research Enquiry

Research Enquiry

A structured approach to answering questions through secondary research. Pupils formulate a research question, select appropriate sources, take and organise notes, synthesise findings from multiple sources, and present their conclusions. Develops information literacy alongside subject knowledge.

question → source_selection → note_taking → synthesis → presentation Assessment: Research report or presentation that answers the original question using evidence from multiple sources, with evaluation of source reliability where appropriate. Teacher note: Use the RESEARCH ENQUIRY template: give pupils a clear question to research using books, websites, or other provided sources. Teach them to select relevant information, make brief notes in their own words, and organise their findings. Guide them to present what they have learned clearly, distinguishing between what different sources say. KS2 question stems:

What question are we trying to answer?

Which sources are most useful for answering this question?

Can you put the key information into your own words?

What did you find out, and which source told you that?

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Equipment and safety

Equipment:

torso model or diagram

mirror (tooth observation)

egg shells + cola/water (tooth decay model)

food chain cards

Safety notes: Egg shell experiment uses cola — no drinking of experimental liquids. Hand washing after handling food items and models. If using mirrors for tooth observation, ensure they are unbreakable. (Hazard level: low)

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Expected outcome

Pupils can describe the journey of food through the digestive system (mouth, oesophagus, stomach, small intestine, large intestine), name and describe functions of different tooth types (incisors, canines, molars), and construct food chains with producers, predators and prey.

Recording format: labelled diagram of digestive system, tooth investigation results, food chain diagram

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Enquiry type

Research Using Secondary Sources

An enquiry where pupils answer scientific questions using information from books, websites, databases, and other secondary sources rather than first-hand investigation. Used when the question cannot be answered by practical investigation in the classroom (e.g. space, evolution, body systems, historical scientific discoveries).

KS2 guidance: At KS2, research enquiries should use age-appropriate sources. Pupils should be guided to check whether information comes from a reliable source. Note-taking should be in the pupil's own words. Presentation formats include posters, labelled diagrams, short reports, and timelines. Topics often include evolution, the solar system, and human body systems. Question stems:

What does the evidence tell us about [topic]?

How do scientists explain [phenomenon]?

What do we know about [topic] and how do we know it?

Teacher scaffold:

What question are we trying to answer?

Where can we find reliable information about this?

What are the key facts and ideas from this source?

Do different sources agree? If not, why might they differ?

What is the answer to our question, based on the evidence?

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Known misconceptions

Food chain arrow direction

What pupils may say: Arrows in food chains point from the predator to the prey — they show 'who eats who'. Correct explanation: Arrows in food chains show the direction of energy transfer, not the direction of eating. The arrow points from the organism being eaten to the organism eating it, showing that energy is transferred from prey to predator. So 'grass -> rabbit -> fox' means energy flows from grass to rabbit to fox. Diagnostic questions:

In the food chain 'grass -> rabbit -> fox', what do the arrows represent?

Which way does the energy flow in a food chain?

Draw a food chain for: lettuce, caterpillar, thrush. Which way do the arrows go?

Digestion happens only in the stomach

What pupils may say: The stomach is the only organ involved in digestion — food goes in and gets digested there. Correct explanation: Digestion begins in the mouth (teeth break down food mechanically; saliva contains enzymes that begin chemical digestion of starch). Food then travels through the oesophagus to the stomach (acid and enzymes), small intestine (most chemical digestion and absorption of nutrients), and large intestine (water absorption). Digestion is a whole-body process involving multiple organs. Diagnostic questions:

Where does digestion start?

What happens in the small intestine? Is it just storage?

Can you name four organs involved in digestion and what each one does?

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Why this study matters

Research enquiry is the appropriate approach here because the digestive system cannot be directly investigated through experiment in a primary classroom. Combining research with physical models (egg shell tooth decay experiment, food chain card sorting) ensures pupils engage actively with the content rather than passively reading, building both knowledge and scientific communication skills.

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Pitfalls to avoid

Pupils think digestion only happens in the stomach — the process starts in the mouth and continues through the intestines

Confusing food chains and food webs — start with simple chains before introducing the complexity of webs

Pupils may think arrows in food chains show 'who eats who' rather than 'energy is transferred to' — clarify arrow direction

Sensitive content

Be sensitive to pupils with dietary restrictions or eating difficulties when discussing food and digestion

Avoid framing food as 'good' or 'bad' — focus on the scientific process of digestion

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Cross-curricular opportunities

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Working scientifically skills (KS2)

These disciplinary skills should be woven through teaching, not taught in isolation:

Identifying and classifying — Sorting and grouping objects, organisms or materials according to their observable characteristics, recognising that things can be classified in more than one way depending on which features are selected.

Making and recording observations with evaluation of method — Conducting observations and measurements using a range of apparatus and methods appropriate to the investigation, and critically evaluating the reliability of those methods with reasoned suggestions for improvement.

Communicating findings — Presenting the outcomes of scientific enquiry in oral and written forms — including explanations, displays and presentations — using appropriate scientific language and representations to convey methods, results and conclusions clearly to others.

Asking relevant questions and selecting enquiry types — Formulating focused scientific questions and selecting the most appropriate enquiry method to answer them, choosing between observing over time, pattern seeking, classifying, comparative tests, fair tests, or secondary research as the situation demands.

Evaluating evidence and understanding scientific knowledge development — Critically evaluating data for random and systematic error, and understanding how scientific methods and theories evolve as new evidence emerges — including the roles of publication, peer review and replication in establishing trustworthy scientific knowledge.

Drawing conclusions and evaluating evidence — Using collected data to draw conclusions, identify causal relationships, make and test predictions, and assess the degree of trust that can be placed in results, recognising when evidence supports or refutes a scientific idea.

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Vocabulary word mat

Prior knowledge (retrieval plan)

Pupils should already know the following from earlier units:

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Scaffolding and inclusion (Y4)

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Knowledge organiser

Key terms:

digestion

oesophagus

stomach

intestine

incisor

canine

molar

enamel

producer

predator

prey

food chain

Core facts (expected standard):

Animal Nutrition: Explaining the role of different nutrients in the body and describing what a balanced diet looks like, using the Eatwell Guide as reference.

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Graph context

Node type: ScienceEnquiry | Study ID: SE-KS2-008 Concept IDs:

SC-KS2-C017: Animal Nutrition (primary)

SC-KS2-C031: Digestive System

SC-KS2-C032: Types and Functions of Teeth

SC-KS2-C033: Food Chains with Producers, Predators and Prey

Cypher query:

``cypher

MATCH (ts:ScienceEnquiry {enquiry_id: 'SE-KS2-008'})

-[:DELIVERS_VIA]->(c:Concept)

-[:HAS_DIFFICULTY_LEVEL]->(dl)

RETURN c.name, dl.label, dl.description

``

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Generated from the UK Curriculum Knowledge Graph — zero LLM generation.