Unformatted text preview: Probability and Ratios Probability
Probability The likelihood that a particular event will occur. Probability
Probability Can determine probability from completed Punnet Squares Example: X Y
Probability of first offspring being a male: X
X XX
XX XY
XY Probability of second offspring being a male:
Probability of third offspring being a male: Probability
Probability Probability does not change after traits show up in an offspring. Same chance still exists for every possibility of being expressed. X Y
Probability of first offspring being a male: 1/2 X X XX XX XY XY Probability of second offspring being a male: 1/2
Probability of third offspring being a male: 1/2 Ratios
Ratios Comparing the number of phenotypes or genotypes of the possible offspring Phenotypic Ratio Comparing the amount of offspring that express each physical trait in a given cross Genotypic Ratio Comparing the amount of offspring that express each allele combination in a given cross Example
Example B
B
b b BB Bb
Bb bb Phenotypic Ratio There are three browns and one green. The ratio is 3:1 Genotypic Ratio There is one homozygous dominant, two heterozygous, and one homozygous recessive. The ratio is 1:2:1...
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 Winter '11
 Harmon
 Probability, Punnet Squares, PROBABILITY Probability

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