Transmission Genetics Worksheet

1. Name _______________________________________ Score ______________
Section _____________________________________ Date ______________
Transmission Genetics (Mendelian)
Worksheet
Directions: Answer the following questions using your notes and textbook.
Define the following:
Allele - Genotype -
Dominant trait - Phenotype -
Recessive trait -
Homozygous trait -
Heterozygous trait -
1. For each genotype below, indicate whether it is heterozygous (He) or homozygous (Ho)
AA _____ Ee ____ Dd _____ mm _____
2. For each of the genotypes below determine what phenotypes would be possible.
Purple flowers are dominant to white flowers. Bobtails in cats are recessive.
PP ___________________ TT ___________________
Pp ___________________ Tt ___________________
pp ___________________ tt ___________________
Brown eyes are dominant to blue eyes
BB ___________________
Bb___________________
bb___________________
3. For each phenotype below, list the genotypes
Round seeds are dominant to wrinkled seeds
RR ___________________
Rr ___________________
rr ___________________
Straight hair is dominant to curly. Pointed heads are dominant to round heads.
______ straight ______ pointed
______ curly ______ round
Long tails are dominant over short tails. Long hair is dominant over short hair.
______ long tail ______ long hair
______ short tail ______ short hair

2. 4. Set up the Punnet squares for each of the crosses listed below.
Round seeds are dominant to wrinkled seeds.
Given RR x rr
What percentage of the offspring will be round?
Given Rr x rr
What percent of the offspring will be round?
Given RR x Rr
What percent of the offspring will be round?
Given Rr x Rr
What percent of the offspring will be round?

3. Practice with Crosses.
1. A TT (tall) plant is crossed with a tt (short plant). What percentage of
the offspring will be tall?
2. A Tt plant is crossed with a Tt plant.
What percentage of the offspring will be short?
3. A heterozygous round seeded plant (Rr) is crossed with a homozygous round seeded plant
(RR). What percentage of the offspring will be homozygous (RR)?
4. Two short haired guinea pigs are mated several times.
Out of 100 offspring, 25 of them have long hair. What are the probable genotypes of the
parents?
__________ x ___________ Show the cross to prove it!