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PUNNETT SQUARE. A Punnett square is a tool used to predict the percentage of genotypes for the offspring of two known parents. PARENT’S GENES. ¼ or 25%. ¼ or 25%. PARENT’S GENES. Each square represents a fraction or percentage. ¼ or 25%. ¼ or 25%. TERMS TO KNOW. TERMS TO KNOW.
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PUNNETT SQUARE A Punnett square is a tool used to predict the percentage of genotypes for the offspring of two known parents. PARENT’SGENES ¼ or 25% ¼ or 25% PARENT’S GENES Each square represents a fraction or percentage. ¼ or 25% ¼ or 25%
HOW TO USE A PUNNETT SQUARE BB: homozygous dominant BB X bb bb: homozygous recessive B B b The parents’ alleles go on the outside of the Punnett square b
HOW TO USE A PUNNETT SQUARE Drop each letter on top into each square. B B B B B B B BB X bb b b b Move each letter on the left side into each square. b b b
WHAT DO THE RESULTS OF A CROSS SHOW? B B If B is the dominant ALLELE for black b Bb Bb and b is the recessive ALLELE for brown Bb Bb b then we can make predictions about the outcomes Phenotype: 100% Black Genotype: 100 % Bb (heterozygous dominant)