Download Let`s try some Punnett Squares

Punnett Squares Practice Worksheet 2
1. In guinea pigs, long hair is dominant to short hair. A pure bred short haired guinea pig is bred with a hybrid
long haired. What does each of those look like? (use H)
Pure bred (homozygous) _______________
Hybrid (heterozygous) _________________
Set up the Punnett square:
What percent of the babies will have Hh as their alleles? ______________
What percent of the babies will be long haired? _____________________
What percent of the babies will be short haired? ____________________
What is the genotypic ratio? _______________________
What is the phenotypic ratio? ______________________
2. In rabbits, black fur is dominant to white fur. If you cross a BB male with a Bb female, what are the possible
genotypes and phenotypes of the offspring? What is the percent chance for each type? Include genotypic and
phenotypic ratios.
Possible combinations
Percent chance
Ratios
Genotypes
Phenotypes
3. In cabbage butterflies, White wings are dominant to yellow wings. If a Ww butterfly is crossed with a ww
butterfly, what are the possible genotypes and phenotypes of the offspring and the percent chance for each?
Include genotypic and phenotypic ratios.
Possible combinations
Genotypes
Phenotypes
Percent chance
Ratios
4. In dogs, there is a hereditary type of deafness caused by a recessive gene. Two dogs that carry the gene for
deafness but have normal hearing are mated. What are the possible genotypes and phenotypes of their
offspring and the percent chance for each? Include genotypic and phenotypic ratios.
Possible combinations
Percent chance
Ratios
Genotypes
Phenotypes
5. Tongue-curling in humans is a dominant genetic trait. Suppose a man who is Tt for tongue-curling marries a
woman who is also Tt for this trait. What are the possible genotypes and phenotypes of their children and the
percent chance for each? Include genotypic and phenotypic ratios.
Possible combinations
Percent chance
Ratios
Genotypes
Phenotypes
6. In guinea pigs, rough coats (with lots of swirly cowlicks) are dominant over smooth coats. If an RR guinea pig
is crossed with an Rr guinea pig, what are the possible genotypes and phenotypes of the offspring? What are
the chances of each? Include genotypic and phenotypic ratios.
Possible combinations
Genotypes
Phenotypes
Percent chance
Ratios