Category
Biology Calculators
Biology calculators for genetics and agronomy: build Punnett squares, predict eye and coat color inheritance, and estimate corn yield from field counts.
Corn Yield Calculator
Estimate corn yield in bushels per acre using plant population, ears per plant, and kernel counts.
Punnett Square Calculator
Generate monohybrid and dihybrid Punnett squares and calculate genotype and phenotype probabilities.
Eye Color Calculator
Predict possible eye colors of offspring based on parent phenotypes using genetic inheritance models.
Coat Color Calculator
Predict offspring coat colors and probabilities for dogs, horses and cats from parent genotypes.
Genetics: predicting inheritance
Most inheritance questions start with a Punnett square: list each parent’s possible gametes, combine them, and count the outcomes. The Punnett Square Calculator builds monohybrid and dihybrid crosses and reports both genotype and phenotype ratios, which is where most homework errors happen.
The Eye Color Calculator and Coat Color Calculator apply the same logic to traits people actually ask about. Eye color uses a simplified model in which brown is dominant over green and green over blue, while coat color models several genes at once for dogs, horses, and cats. Real traits are influenced by more genes than any simple model includes, so treat results as probabilities, not predictions for a single child or litter.
Agronomy: estimating corn yield before harvest
The yield component method estimates bushels per acre from counts you can take in the field: plants per acre, ears per plant, kernel rows per ear, and kernels per row. The Corn Yield Calculator multiplies these out and divides by kernels per bushel, using 90,000 as the default for average kernel size.
Because kernel size is not known until grain fill is complete, early estimates can be off. Sampling several spots across a field gives a far better picture than one representative-looking row.
Key formulas
- Monohybrid cross
- Aa × Aa → 1 AA : 2 Aa : 1 aa
- Dihybrid cross
- AaBb × AaBb → 9 : 3 : 3 : 1 phenotypes
- Corn yield
- bu/acre = (ears/acre × kernels/ear) ÷ 90,000
Getting accurate results
- Write each parent’s genotype before building a square; most mistakes come from listing gametes incorrectly.
- Probabilities apply to each offspring independently, so small families often differ from the expected ratio.
- For corn, take counts from at least five spots per field and average them.
- Lower the kernels-per-bushel figure if kernels look large and well filled, and raise it in a stressed year.
Frequently asked questions
- Can two blue-eyed parents have a child with a different eye color?
- A simple one-gene model says every child will have blue eyes. Because other genes also play a part, the calculator’s population-based model allows about a 1% chance of green eyes.
- What is the difference between genotype and phenotype?
- Genotype is the pair of alleles an individual carries; phenotype is the trait you can observe. Different genotypes can produce the same phenotype.
- How early can I estimate corn yield?
- The component method works from about the milk stage onward, once kernel counts are set. Accuracy improves as kernels fill.
- Why do coat color results depend on genotype, not just color?
- The same coat color can come from different genotypes, and hidden recessive alleles change what offspring can inherit.
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