Review of Genetics
1. For each of the following, indicate whether it is homozygous
dominant (HD), homozygous recessive (HR) or heterozygous (HE).
a. HH
f. Ss
b. Hh
g. Qq
c. Cc
h. PP
d. cc
i. rr
e. SS
2. For each of the genotypes below determine what phenotypes would be
possible.
a. Purple flowers are dominant to white flowers
i. PP
ii. Pp
iii. pp
b. Straight hair shows INCOMPLETE dominance to curly hair.
i. SS
ii. Ss
iii. ss
c. Red and white coloration in flowers is CO-DOMINANT.
i. RR
ii. R’R’
iii. RR’
3. For each of the phenotypes below determine what genotypes would be
possible.
a. Purple flowers are dominant to white flowers
i. Purple
ii. Purple
iii. White
b. Straight hair shows INCOMPLETE dominance to curly hair.
i. Straight
ii. Wavy
iii. Curly
c. Red and white coloration in flowers is CO-DOMINANT.
i. Red
ii. White
iii. Red/White
4. Hemophilia is a SEX-LINKED disorder.
a. Show ALL possible genotypes and phenotypes for this disorder.
b. Show the Punnett Square between a carrier female and a
hemophiliac male.
c. What are the conditions of their offspring (in percents)?
5. Short hair is COMPLETELY DOMINANT to long hair in guinea pigs.
a. Show ALL possible genotypes and phenotypes for hair length in
guinea pigs.
b. Show the Punnett Square between a heterozygous short guinea pig
and a long haired guinea pig.
c. How many guinea pig offspring will have short hair? How many will
have long hair?
6. Blood type in humans is a MULTIPLE ALLELE trait.
a. Show ALL possible genotypes and phenotypes for human blood
types.
b. Show the Punnett Square between a female with AB blood and a
male with homozygous A blood.
c. What are the blood types of their offspring (in percents)?
7. Coat coloration in horses is the result of a CO-DOMINANT relationship. The
dominant conditions are red and white. The co-dominant condition is
called roan.
a. Show ALL possible genotypes and phenotypes for coat coloration in
horses.
b. Show the Punnett Square between a red horse and a roan horse.
c. What is the coat coloration of the offspring (in percents)?
8. Coloration of the four o’clock flower is the result of an INCOMPLETE
DOMINANCE relationship. Red is the dominant trait and white is the
recessive trait.
a. Show ALL possible genotypes and phenotypes for flower coloration.
b. Show the Punnett Square between a pink flower and a white flower.
c. What is the flower coloration of the offspring (in percents)?