Lesson 2 of 27 in this sequence

Not completed yet

Saved on this device only — not synced to an account yet.

Learning path

Step 2 of 27

Continue the sequence

ResumeReturn to this step ReviewRevisit the core idea RemediateGet repair practice Next stepChoose the next lesson manually

Completion

Review objectives and instruction
Complete the activity with manual learner confirmation
Answer every understanding-check item
Show completion feedback and reward only after the learner finishes the check

Progress

Step 2/27
15 content types
AI help source context available
Auto-advance blocked

Review objectives and instruction

AI help

Available only with source grounding, privacy limits, age controls, and measurement.

AI source context

Bones Are Hard Parts That Hold You Up · How My Body Moves · bones · skeleton

Evidence: local lesson AI-help metadata only; source-grounding, privacy, age-safety, and measurement hooks do not prove real model quality, production telemetry, child AI approval, or AI tutor production readiness

Production AI readiness not claimed

AI source context

Assessment shape

Local lesson assessment shape is complete.

Local shape only; production answer-attempt telemetry, live ownership/RLS evidence, mastery interpretation, release, and production readiness are not claimed here.

Objectives: 4
Activity: Prompt ready
Quiz items: 3 items, 3 answer keys, 3 explanations
Reward: Completion reward ready

Assessment progress stays manual: do not auto-advance through uncertain answers, failed writes, consent, media, payment, learner choice, or AI-assisted checks.

Learning-loop evidence: Content-map contract only; persistence and production learner-progress writes require route/API evidence.

Manual policy: assessment, media, consent, payment, learner choice, failed writes, and AI-uncertain help stay under learner control.

Prerequisite: Complete or review Bones and Muscles Help Me Move; Use with parent or guardian controls for child learners

AI guardrails

Privacy

Do not send raw child free text without consent
Use source excerpts and non-identifying progress state only
Asset is not registry-gated

Age safety

Apply junior audience controls before AI-help claims
Keep child learner AI paths behind guardian/product review evidence before readiness claims

Measurement

Log AI help usage by surface and asset slug
Evaluate answer quality against source-grounded rubric before production-readiness claims
Tie remediation prompts to completion, retry, or review outcomes

Local AI-help guardrails only; they do not prove guardian approval, production telemetry, model evaluation, release, deployment, or AI tutor production readiness.

Source and rights

Source path: koydo-app/scripts/curriculum-authoring
License: ai-generated-koydo
Attribution: Attribution decision needs owner review
AI provenance: claude-opus-4-8

Source review gates: attribution_missing

Local source evidence only; this does not prove publication rights, attribution approval, AI provenance clearance, release, deployment, or production readiness.

Route review

Current route: /library/junior/anatomy_physiology/en/lesson/bones-give-the-body-shape
Route source: Fallback route needs owner canonical review
Candidate route: /library/junior/anatomy_physiology/en/lesson/bones-give-the-body-shape

Local route evidence only; fallback candidates need owner-approved canonical route policy before route writes, production discoverability, or readiness claims.

Content gates: canonical_target_web_missing_uses_library_fallback

lessonslessonslesson objectivesmedia scenesdrillspractice setsquizzesfeedbackcharacterscitationsconcept mapsprogressresumereviewremediationnext steps

Bones Are Hard Parts That Hold You Up

with Medi

Medi stands in a cozy classroom next to a friendly skeleton model, gently tapping one of its ribs and smiling at a group of curious young children sitting on the floor.

Identify bones as the hard parts inside your body.
Explain that bones give your body its shape.
Describe how bones help you stand up and move.
Compare your body's bones to a building frame that holds everything up.

Key terms

bone: A hard, stiff part inside your body that gives it shape.
skeleton: All the bones in your body joined together as a frame.
skull: The bony case in your head that protects your brain.
rib: A curved chest bone that protects your heart and lungs.

Bones Are Hard and Strong

If you press on your arm or your knee, you feel something hard under your skin. That is a bone. Bones are stiff and tough, not soft and squishy. Their hardness is exactly what lets them hold your weight without bending, so you can stand and sit up straight all day.

Your Skeleton Holds You Up

You have more than 200 bones, and all of them together make your skeleton. Your skeleton is like the frame of a building or the metal frame of a bicycle. It gives your whole body its shape and keeps it from flopping over, which is why you look like a person and not a puddle.

Bones Also Protect You

Some bones do more than hold you up; they also act like shields. Your skull is a hard bony case that protects your soft brain, and your curved rib bones make a cage that guards your heart and lungs. So bones give shape, give support, and keep your most important soft parts safe.

Worked examples

Explain why a jellyfish has no fixed shape.

A jellyfish has no bones inside its body.
With no hard frame, there is nothing stiff to hold a shape.
So its soft body droops and changes shape, unlike a person with a skeleton.

Answer: A jellyfish has no bones, so it has no firm frame to give it a fixed shape.

Decide which is most like your bones: a pillow or a bicycle frame.

A pillow is soft and squishy and cannot hold anything up.
A bicycle frame is hard and stiff and holds the whole bike together.
Bones are hard and hold your body up, just like the bike frame.

Answer: A bicycle frame is most like your bones.

Hi friends! My name is Medi, and today we are going to learn about something amazing inside your body — your BONES! Feel your arm. Do you feel something hard under your skin? That is a bone! Bones are hard parts that live inside you. You cannot see them, but they are there. You have bones all over your body. You have bones in your arms, your legs, your back, and even your fingers! All your bones together make something called a SKELETON. Here is a great way to think about it. Imagine building a house. First, workers put up a strong frame — tall pieces of wood or metal that hold the whole house up. Without that frame, the house would fall down flat! Your bones are just like that frame. They hold your whole body up. Because of your bones, you can stand tall, sit up straight, and run around and play. Without your bones, your body would be soft and floppy — like a stuffed animal with no stuffing inside! Your bones give your body its shape. That means your bones are the reason you look like YOU.

Activity

Look at each picture and sort it — does it have a hard frame inside, or is it soft and floppy with no frame?

Practice

Name two places in your body where you can feel a bone.

Why would your body be floppy if you had no bones inside it?

Common mistakes to avoid

Bones are soft and squishy.Bones are hard and stiff, and that hardness is what lets them hold your body up.
Bones only sit there doing nothing.Bones give your body shape, support your weight, and protect soft parts like your brain.

Check your understanding

What do bones do for your body?

Your friend says bones are soft and squishy. Are they right?

Which thing is most like the bones inside your body?

Recap

Bones are the hard parts inside you that join together to form your skeleton. Your skeleton gives your body its shape, holds you up like a building frame, and protects soft parts like your brain.

Reflect

Why do you think your skull and ribs are shaped to curve around your soft parts?