Idea or model
Mendelian inheritance
Mendel's pea crosses showed that traits are inherited as separate units, giving predictable ratios such as 3 to 1.
Punnett square
A grid that predicts the possible offspring genotypes from a cross between two parents.Source: OpenStax, 2018Source: Abbott & Fairbanks, 2016
Step 4 of 7ReadingIdea or model
How Punnett square connects
Punnett square describes
Punnett square uses
Idea or model
Genotype
The particular variants an individual carries at a location in the genome, often written as letters such as Bb.
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Sources & further reading
The explanations on this page are our own summaries of these sources. Follow a link to read the original; if anything here disagrees with it, the original wins. How we choose and check sources.
Biology 2e (opens the original in a new tab)
OpenStax (2018). OpenStax, Rice University.
Free introductory college textbook.
TextbookEducationalLicence: CC BY-NC-SA 4.0 (linked, not reused)
Experiments on Plant Hybrids by Gregor Mendel (opens the original in a new tab)
Abbott S, Fairbanks DJ (2016). Genetics 204:407-422.
A modern English translation of Mendel's 1866 paper.
Peer-reviewedTranslation