Freckles punnett square

A Punnett square can show possible allele combinations under a stated inheritance model, but it cannot by itself establish how a complex human trait is inherited. Freckling is influenced by pigmentation biology, genetic variation, and environmental exposure.

How it works

Older classroom examples sometimes label freckles as a simple dominant trait. That simplification is not a complete account of human pigmentation, which involves multiple genes and can vary with sunlight and age.

Example or application

A two-allele square can still teach how to combine hypothetical parental alleles. Its outcome describes probabilities within that model, not a diagnosis or a reliable prediction for a particular person.

Scope and limits

Do not infer a person’s genotype or ancestry from freckles. Human traits often do not follow the single-gene, complete-dominance pattern used in introductory exercises.

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