Punnett Squares

Punnett Squares : A Model used to show the possible ways genes can combine during fertilization.

Punnett Squares Punnett Squares Helps you keep track of traits.

Dominant and recessive alleles are represented by letters. Punnett Squares Dominant and recessive alleles are represented by letters.

Punnett Squares A capital letter (T) is used for dominant alleles. T

A lowercase letter (t) is used for recessive alleles. Punnett Squares A lowercase letter (t) is used for recessive alleles. t

Punnett Squares If you wanted to know the type of offspring a cross between two parents would produce, you can use a punnett square. Tt x Tt TT,Tt for tall tt for short

Punnett Squares The letters representing the alleles from one parent are placed along the top of the square. T t

Punnett Squares The letters representing the two alleles from the second Parent are places along the side of the square. T t

Punnett Squares T t x T t T t T t

Punnett Squares Squares are filled by writing the letter at the top beside the letter on the side. T t TT Tt t t T t

Punnett Squares The letters in each of the squares represents the Genotypes of the offspring that the parents could produce. TT Tt t t T t TT Tt t t T t

Punnett Squares The genotype (genetic makeup) can be used to predict the phenotype (physical appearance) of the offspring.

Punnett Sqaures Genotype Phenotype TT tall Tt tall Tt tall t t short

Punnett Squares Probability: the ratio that a particular event could occur. 3:1 3 would be tall 1 would be short out of 4 offspring

Punnett Squares: Help you keep track of traits. Predict genotype and phenotype. Calculate probability.