Safety, privacy and evidence boundary
Use fictional organisms, coins/cards, and published-style datasets. Do not require personal family histories, ancestry testing, fertility information, medical pedigrees, or personal genetic data. Trait inheritance never ranks human worth.
Explicit science instruction
A pedigree records relationships and observed trait categories across generations. It can be used to test whether inheritance patterns are consistent with autosomal dominant, autosomal recessive, X-linked, mitochondrial, or other simplified models.
Pedigrees rarely prove a mechanism by themselves. Small family size, missing information, adoption, non-paternity assumptions, variable penetrance, phenocopies, and classification errors can change interpretation. This course uses fictional or historical-public examples only.
Vocabulary: pedigree; proband; carrier; autosomal; dominant; recessive; inference; penetrance.
Worked example with reasoning
In a fictional pedigree, two unaffected parents have an affected child under a fully penetrant simple model. That is consistent with autosomal recessive inheritance if both parents are carriers, but it is not uniquely proven without additional evidence.
Guided question
Why should a pedigree conclusion usually be phrased “consistent with” rather than “proves”?
Independent work
- Interpret a fictional three-generation pedigree.
- List two models ruled out by one relationship pattern.
- Identify ambiguous genotypes.
- State two real-world factors the simplified pedigree omits.
Misconception check
Pedigrees are not permission to infer relatives' health, paternity, ancestry, or carrier status from personal family information.
Formative understanding check
Can an unaffected person be a carrier in a recessive model?
Worked response
Yes, a heterozygous carrier can be unaffected if the model assumes a recessive phenotype.
Open-book formative practice only; not an official mastery attempt or grade.
Mentor evidence conference
Ask Archaemenes to challenge your probability, evidence classification, model assumptions, and limitations. The mentor does not infer personal genetics or provide protected assessment answers.
Open ArchaemenesTeacher guidance
Foundation: use genotype-possibility labels. Core: defend inference with explicit assumptions. Extended: compare competing pedigree models and rank what additional evidence would be most diagnostic.
Preserve learning evidence
Keep models, calculations, corrections, and limitations in the matching Week 21 evidence field.
Return to evidence workspace