ScienceEcosystems & HabitatsAges 12–13

Chromosomes, Genes & DNA

Describe the relationship between chromosomes, genes, and DNA in heredity, including the double helix structure of DNA and the historical roles of Watson, Crick, Franklin, and Wilkins

Lesson

Set out your lesson

Connect genes, DNA and chromosomes without a false containment hierarchy.

Before teaching

Activity

Can attend to a short explanation and respond orally, by pointing, drawing or writing; check relevant prerequisite understanding rather than assuming age proves readiness.

Policy

Check readiness rather than assuming age or source graph order establishes attainment.

Printer, credit, and teaching notes

Materials

Prepared passage, diagram materials are available in each step.

Preparation

Open the teaching material first. Keep the adult key and check sheet separate until their named stage. No printing, purchase or external media is required for the supplied adapted text tasks.

Safety

Use the supplied text/schematic indoors. Do not collect, taste, touch or disturb wildlife or unknown materials. Discussion does not require a personal experience.

Optional Observation

Only record a real observation after the activity is actually carried out safely; otherwise mark not carried out.

Materials are ready in each step. Use them on screen or print just the current step. Put teaching examples aside before the learner tries.

Next: Show

Adult extras

What this lesson covers and its limits

These are bounded opportunities, not learner attainment. Partial and blocked source requirements remain so.

partial: Describe the relationship between chromosomes, genes, and DNA in heredity, including the double helix structure of DNA and the historical roles of Watson, Crick, Franklin, and Wilkins
Bounded task opportunity only; this task samples the clause using supported reconstruction of supplied hierarchy/strand scaffold; researcher recall evidence, not full coverage or learner attainment.
blocked: Explains the hierarchy: DNA → gene → chromosome → nucleus → cell
Exact source demand not established: Canonical DNA → gene → chromosome hierarchy is misleading: gene is a DNA segment, not a container for DNA.; Canonical human body cells claim has exceptions; most mature red blood cells have no nucleus. Historical contributions require more than crediting only the model builders. Real observation/media-dependent evidence remains conditional where required.
partial: Describes what a gene is and what it codes for
Bounded task opportunity only; this task samples the clause using supported reconstruction of supplied hierarchy/strand scaffold; researcher recall evidence, not full coverage or learner attainment.
blocked: States that human body cells contain 46 chromosomes in 23 pairs
Exact source demand not established: Canonical DNA → gene → chromosome hierarchy is misleading: gene is a DNA segment, not a container for DNA.; Canonical human body cells claim has exceptions; most mature red blood cells have no nucleus. Historical contributions require more than crediting only the model builders. Real observation/media-dependent evidence remains conditional where required.
partial: Describes the contributions of Watson, Crick, Franklin, and Wilkins to the discovery of DNA structure
Bounded task opportunity only; this task samples the clause using supported reconstruction of supplied hierarchy/strand scaffold; researcher recall evidence, not full coverage or learner attainment.
partial: If {{name}} was asked what DNA actually is and where it is in the body, could they explain the relationship between DNA, genes, and chromosomes — and say roughly how many chromosomes a human cell has?
Bounded task opportunity only; this task samples the clause using supported reconstruction of supplied hierarchy/strand scaffold; researcher recall evidence, not full coverage or learner attainment.

Canonical DNA → gene → chromosome hierarchy is misleading: gene is a DNA segment, not a container for DNA.
Canonical human body cells claim has exceptions; most mature red blood cells have no nucleus. Historical contributions require more than crediting only the model builders.

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Family records and proof options

Keep a record of your learning

Save photos, notes, and attendance. Export a proof packet for compliance or portfolio reviews.

View learner plans ($12/mo per learner) See sample family archive

Learning resources

Extra practice links — they do not replace Gakuva’s teaching approach.

PhET Interactive Simulations · Practice link — not the full lesson

Natural Selection

Open practice(new tab)

Before you open · source notes

Natural Selection supports hands-on exploration for Chromosomes, Genes & DNA. Not every lab worksheet.

Free interactive page, no sign-in required for the tested path.

Before you open

Ask the learner what they changed in the sim or page and what they observed.

Opening this link does not save learning or assess mastery.

Source, access and review notes

Public PhET Interactive Simulations page. An anonymous GET on 2026-11-12 returned HTTP 200 with no login or payment prompt for this URL. Opening the link does not save practice or assess mastery. An adult should preview and guide the learner.

PhET Interactive Simulations. “Natural Selection.” External page; Gakuva does not copy, host, embed, or redistribute materials.

Unknown — link only

Check understanding

Explains the hierarchy: DNA → gene → chromosome → nucleus → cell
Describes what a gene is and what it codes for
States that human body cells contain 46 chromosomes in 23 pairs
Describes the contributions of Watson, Crick, Franklin, and Wilkins to the discovery of DNA structure

“If your child was asked what DNA actually is and where it is in the body, could they explain the relationship between DNA, genes, and chromosomes — and say roughly how many chromosomes a human cell has?”

Curriculum record

Type: Conceptual
Subject: Science
Domain: Ecosystems & Habitats
Age range: Ages 12–13

Standards

ngss-ms:MS-LS3-1uk-nc-2013:KS3.Sci.Bio.Adaptation.5

Curriculum