Biology · Molecular Biology
Build a DNA model and explain replication
Make a twistable DNA model with colour-coded bases and use it to demonstrate replication.
- DifficultyBeginner
- Estimated time1 day
- BudgetUnder ₹250
- ClassClass 8–10
- TeamSolo or up to 3
- You needHousehold materials
Prerequisites: None beyond your class work
Original · by TechnifyedSchool ExhibitionWorking ModelBeginner friendlyLow cost
Overview
Make a twistable DNA model with colour-coded bases and use it to demonstrate replication.
Skills you will use
Materials and tools
- Coloured straws or beads in four colours
- Wire or thread
- Two long strips for the backbones
- Tape
- Labels
Step-by-step roadmap
Start
You will finish with: a labelled model and a two-minute explanation of base pairing and replication.
- 1
Prerequisites
Nothing special to know first. Then collect the 5 items in the materials list.
- 2
Learn
Read up on molecular biology: base pairing, DNA, double helix. Your textbook chapter and one short video are enough.
- 3
Plan
Sketch the design, list every part with its price and decide how you will know it works.
- 4
Build
- Assign a colour to A, T, G and C.
- Join pairs A with T and G with C as rungs.
- Fix twelve rungs between two backbones and twist into a helix.
- Make the model unzip down the middle.
- Show how each half builds a new partner strand.
- 5
Test
Run it ten times in a row. Note every failure, fix the cause and test again.
- 6
Document
Photograph each build stage, keep the circuit or drawing, and note what failed and how you fixed it. Report structure
- 7
Present
Demonstrate it working first, then explain how it works and what you would improve. Presentation structure
- 8
Publish
Share a short video, the parts list and the drawing or code so someone else can build it.
Expected outcome
A labelled model and a two-minute explanation of base pairing and replication.
Other versions of this project
Advanced version
Add a messenger RNA strand and demonstrate transcription.
Science fair mode
Text marked "You write this" is a prompt for your own work; everything else is specific to this project.
- Problem
- You write thisWrite your question as: How does [what you change] affect [what you measure]?
- Hypothesis
- You write thisWrite it as: If [I change this], then [this will happen], because [reason].
- Variables
- You write thisName the one thing you change (independent), the thing you measure (dependent) and what you keep the same (controlled).
Materials and procedure are in Materials and the Roadmap.
Observation table
You write thisDraw a table with one column for what you change, one for each repeat reading and one for the average.
- Graph
- You write thisPlot what you changed along the bottom and what you measured up the side; use a bar chart for categories and a line graph for numbers.
- Results
- You write thisState what the graph shows in one or two sentences, with numbers.
- Conclusion
- You write thisSay whether the result supports your hypothesis and why you think so.
Display board
- Title and your name
- Question
- Hypothesis
- Materials
- Procedure (with photos)
- Data table and graph
- Conclusion
- What you would do next
Questions judges ask
- What would you change if you did this again?
- What was your biggest source of error, and how did you reduce it?
- Where is this idea used in real life?
Working as a team
Solo or up to 3. Suggested roles:
Report and presentation
Report structure
- Title and aim
- The problem it solves
- How it works (principle)
- Parts list with cost
- Design: drawing, circuit or block diagram
- Build steps
- Testing and results
- Problems faced and fixes
- Limitations
- Future improvements
- References
Presentation structure
- The problem
- The idea
- How it works (one diagram)
- Parts and cost
- The build (photos)
- Live demo or video
- Test results
- What did not work
- Next version
Viva questions
Prepare your own answers to these before you present.
- What is the aim of your project, in one sentence?
- What is the principle behind it?
- Why did you choose these materials or tools?
- What result did you get, and was it what you expected?
- What went wrong and how did you fix it?
- How could this be improved or used in real life?
Resources
Source and attribution
Original
Written by Technifyed. Free to use for your own school or college project; write the report in your own words. Added 1 Oct 2026.
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