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Punnett Squares & calculating percentages. Pg 125. Punnett Squares. What are punnett squares? What do the letters in a punnett square mean? What is a genotype? What is a phenotype?. A tool used to predict Mendelian genetics.
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Punnett Squares • What are punnett squares? • What do the letters in a punnett square mean? • What is a genotype? • What is a phenotype? • A tool used to predict Mendelian genetics. • An uppercase letter is a dominate allele, and a lower case letter is a recessive allele. • A genotype is its genetic makeup • A phenotype is its how the organism looks as a result of its genotype
Punnett Square • One dog carries heterozygous, black-fur traits (Bb), and its mate carries homogeneous, blond-fur traits (bb). Use a Punnett square to determine the probability of one of their puppies having black fur. • What you know: dominant allele is B Recessive allele is b • What do we need to find: What is the probability of a puppies fur being black
Punnett Square Black dog (Bb) Blonde dog (bb) Black dog Blonde dog
Punnett Square Black dog Black dog (Bb) Blonde dog (bb) There are two Bb genotypes and four possible outcomes %(black fur)= number of ways to get black fur number of possible outcomes Blonde dog
Punnett Square practice 1. In peas, the color yellow(Y) is dominant to the color green (y). According to the Punnett square, what is the probability of an offspring being yellow? Parent (Yy) Parent (Yy)
Punnett squares 2. What was the probability of an offspring having the yy genotype?