Punnett Square Vocabulary Term Synonyms Definition Example Allele A letter that represents a genetic trait B = brown eye color Parents P generation The parents of a cross, the ones contributing egg & sperm (found on the outside of the Punnett square) Offspring Children Kids F1 generation (F2 generation) The potential children produced in a cross (found in the inside of the Punnett square) Dominant “Big” Requires only one allele for the trait to show BB or Bb has brown eyes Recessive “Little” Requires two allele for the trait to show Only bb has blue eyes Genotype Gene type What a person’s alleles (letters) are BB Bb bb Phenotype Physical type What a person looks like Blue eyes Heterozygous Hybrid Carrier Having 2 alleles that are different Homozygous Pure bred Pure breeding True bred True breeding Having 2 alleles that are the same

Punnett Square Notes Using the diagram above, see if Punnett Squares are used to predict the genotypes and phenotypes of the potential offspring produced by a cross (mating). Allele carried by father’s sperm goes here This is a monohybrid cross, because we are only looking at the results of one trait. The mother and the father are considered the P generation. Allele carried by mother’s egg goes here Using the diagram above, see if you can fill in the Punnett square To the left.

Punnett Square Generations Fill in the Punnett Square below for the parental cross and F1 offspring Fill in the Punnett Square below for the F1 cross and F2 offspring

Punnett Square Ratios & Percentages T = tall (dominant) t = short (recessive) Generation Punnett Square Genotypes & Percentages Genotypes & Ratios Phenotypes & Percentages Phenotypes & Parental Cross F1 Generation (offspring) F1 Cross F2 Generation (offspring)