Punnett Square Generator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t4-146

Effect

Computation or source lookup only

Input and validation requirements

The zero-trait input creates an empty cross with a normalization denominator of zero, so genotype and phenotype ratios are undefined; the instrument must reject it. The unspecified dominance convention also changes phenotype classification unless an explicit allele convention is enforced.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "parent1_genotype": "Aa",
    "parent2_genotype": "Aa",
    "number_of_traits": 1,
    "dominance": {
      "A": "dominant",
      "a": "recessive"
    }
  },
  "expected_outputs": {
    "punnett_grid": [
      [
        "AA",
        "Aa"
      ],
      [
        "Aa",
        "aa"
      ]
    ],
    "genotype_ratio": {
      "AA": 1,
      "Aa": 2,
      "aa": 1
    },
    "phenotype_ratio": {
      "dominant_A": 3,
      "recessive_a": 1
    }
  },
  "working": "Each parent produces gametes A and a. The 2 x 2 grid has AA, Aa, Aa, aa, for 4 total outcomes. Genotype counts: AA = 1, Aa = 2, aa = 1, so the ratio is 1:2:1. Dominant phenotype count = AA + Aa = 1 + 2 = 3. Recessive phenotype count = aa = 1. Phenotype ratio = 3:1."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json