Punnett Square Practice

1
Punnett Square Practice

• Show a cross between a Heterozygous (Bb) animal
  with a homozygous purebred (bb).
• B Black Fur
• b White Fur
• What are the genotypes of the offspring?
• What are the phenotypes of the offspring.

2
Punnett Squares Predict Probability

• In a genetic cross, the allele that each parent
  will pass on to its offspring is based on
  probability.
• You can determine what percentage chance you have
  of passing on certain alleles.
• Since there are four squares each square
  represents 25 (4 x 25 100)

3
Probability Example

• What percentage of the offspring are
  Heterozygous?
• What percentage of the offspring are homozygous?
  
• What would the ratio of the offspring be?
• 22 or 11

4
Probability Examples