Understanding starts with exploring.
Biology Lab is a free collection of interactive tools for students, teachers, and anyone who learns by trying things. Cross two parents, change a growth rate, translate a gene, and follow the reasoning step by step.
How the tools calculate
Every calculation runs directly in your browser using the standard models taught in introductory biology. Displayed values are rounded, while calculations use full numeric precision.
- Punnett squares assume independent assortment, random fertilization, and complete dominance unless a tool says otherwise. Real inheritance also involves linkage, incomplete dominance, codominance, sex linkage, and environmental effects.
- Hardy–Weinberg calculations describe a large, randomly mating population with no selection, mutation, or migration. Deviations from expected values are interesting precisely because those assumptions are rarely met.
- Growth models are idealized. Exponential and logistic curves describe trends, not the exact size of a real population.
- DNA translation uses the standard genetic code and reads the entered sequence as the coding strand, 5′ to 3′. Mitochondrial and some microbial genomes use slightly different codes.
- Lab calculators such as dilution, magnification, and water potential use textbook formulas and the units shown beside each field.
Use these tools for learning and check independent sources before applying results to research, clinical, or safety-critical work. Nothing here is medical advice.
Your data
You do not need an account. Calculator inputs, including any DNA sequence you type, are processed on your device and are not sent to an application server. Practice best scores are saved in your browser’s local storage; clearing browser data removes them. Anonymous usage analytics may be enabled to measure how the site is used. The hosting provider may process normal access logs, and fonts load from Google Fonts.
Printables
Printable diagrams and Punnett grids are generated as SVG files. Use A4 or Letter paper at 100% scale, and turn off browser headers and footers for a clean sheet.
Help improve the lab
Have a suggestion, found a mistake, or spotted something that could work better? Email info@thebiologylab.org. Include the page link and a short description so we can take a closer look.