A grid used to predict the possible genotypes and probabilities of offspring from a cross.
List the possible gametes of each parent along the top and side, then fill the grid to show the combinations. Each box has equal probability, so ratios give probabilities.
For larger crosses, the product rule (multiply independent probabilities) and the sum rule (add alternatives) are faster.
A grid used to predict the possible genotypes and probabilities of offspring from a cross.
Punnett Squares is one of the 54 topics in Genetics. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Law of Independent Assortment, Monohybrid Cross, Mendel's Pea Experiments.
For a 3:1 ratio, the chance of a Tt x Tt offspring showing the recessive trait is 1/4.
Punnett Squares is a Beginner topic, so no earlier topic is required. Other Beginner topics in Genetics that pair well with it include Heredity, Gene, Allele.
The closest topics to Punnett Squares are Law of Independent Assortment, Monohybrid Cross, Mendel's Pea Experiments, Dihybrid Cross. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Punnett Squares. To practise the whole of Genetics, use the Genetics quiz.
Punnett Squares: A grid used to predict the possible genotypes and probabilities of offspring from a cross. Law of Independent Assortment: Alleles of different genes are distributed to gametes independently when the genes lie on separate chromosomes. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Law of Independent Assortment and explain the difference aloud. Finally, take the Genetics quiz and come back to this page for any question you miss.
Alleles of different genes are distributed to gametes independently when the genes lie on separate chromosomes.
🧬 GeneticsA cross following one gene with two alleles, giving a 3:1 phenotype ratio in the F2 generation.
🧬 GeneticsGregor Mendel crossed pea plants to discover the basic laws of inheritance in the 1860s.
🧬 GeneticsA cross following two genes at once, giving a 9:3:3:1 phenotype ratio when genes assort independently.
🧬 Genetics