Plant Genetics & Mendelian Inheritance Simulator
Cross two parent plants for flower colour, seed shape or height, build the Punnett square, then breed real offspring and compare the ratio to Mendel's theory.
Green = theoretical Mendelian percentage, orange = your experimental result.
About the Plant Genetics & Mendelian Inheritance Simulator
Free plant genetics & mendelian inheritance simulator. Cross two parent plants for flower colour, seed shape or height, build the Punnett square, then breed real offspring and compare the ratio to Mendel's theory. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for botany, the plant genetics & mendelian inheritance simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Cross two parent plants for flower colour, seed shape or height, build the Punnett square, then breed real offspring and compare the ratio to Mendel's theory. Use it to explore botany ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Plant Genetics & Mendelian Inheritance Simulator
- Use the controls to change Number of offspring. The simulation reacts instantly.
- Pick an option such as Monohybrid, Dihybrid, 10, 100 to switch modes or load an example.
- Press "Breed offspring", "Reset to defaults", "📄 Lab Report" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Cross Dd × Dd for one trait, breed 10 offspring, then 10000, and compare the bars.
- Switch to a dihybrid cross and check the ratio matches 9:3:3:1.
- Cross a homozygous recessive with a heterozygote and predict the ratio before breeding.
- Read the Punnett square and predict the ratio before pressing Breed.
Key ideas you can learn
- Mendel's law of segregation: each parent's two alleles for a trait separate into gametes with equal probability.
- Mendel's law of independent assortment: alleles for different traits are inherited independently of each other.
- A monohybrid cross of two heterozygotes gives a 3:1 phenotype ratio; a dihybrid cross of two double heterozygotes gives a 9:3:3:1 ratio.
- Real offspring are produced by genuinely random inheritance, so small samples can drift from the theoretical ratio while large samples converge on it (the law of large numbers).
Where this is used in the real world
Plant breeders use exactly this Mendelian logic - and modern DNA testing of the underlying genes - to predict and select for traits like disease resistance, yield and colour in new crop varieties.
Who is this simulation for?
Students, teachers and curious learners of all ages.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Why does a cross between two heterozygous (Dd × Dd) plants give a 3:1 ratio?
The Punnett square shows four equally likely combinations - DD, Dd, Dd, dd - and three of them (DD, Dd, Dd) show the dominant phenotype while only dd shows the recessive one, giving 3:1.
Why might 10 simulated offspring not show exactly the predicted ratio?
Inheritance is random for each individual, so with a small sample chance alone can skew the result; breeding 1000 or 10000 offspring averages out that noise and matches the theoretical ratio much more closely.
Is the Plant Genetics & Mendelian Inheritance Simulator free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Plant Genetics & Mendelian Inheritance Simulator work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.