Canossa College
San Pablo City
General Biology 2
SY. 2020-2021
INCOMPLETE DOMINANCE WORKSHEET
Name: Noblejas, Beanca Denise N.
Teacher: Ms. Lourdes Claire Ignacio
Section: STEM 12 – St. Gianna (Allied Health)
Answer the following questions. Provide the following: Given traits: P1: Punnett Square: GT: PT: Answer the given
questions in the problem. Express probabilities as percentages
1. Explain the definition of incomplete dominance.
Incomplete dominance is when a dominant allele, does not completely mask
the effects of the recessive allele, and the organism’s resulting physical appearance
shows a blending of both alleles. It is also called semi-dominance or partial
dominance.
2. In some chickens the gene for feather color is controlled by codominance. The allele for black is B and the allele for
white is W. The heterozygous PT is known erminette.
a) What is the GT for black chicken? BB
b) What is the GT for white chicken? WW
c) What is the GT for erminette chicken? BW
3. If two erminette chickens were crossed, what is the probability that:
a. They would have a black chick? 25%
b. They would have a white chick? 25%
B
W
B
BB
BW
W
BW
WW
4. A black chicken and a white chicken are crossed. What is the probability that they will have erminette chicks?
100% eminette chicks.
B
B
W
BW
BW
W
BW
BW
5. In snapdragons, flower color is controlled by the incomplete dominance. The two alleles are red (R) and white (R’).
The heterozygous GT is expressed as pink.
a. What is the PT of a plant with the GT RR? Red
b. What is the PT of a plant with the GT R’R’? White
c. What is the PT of a plant with the GT RR’? Pink
6. A pink-flowered plant is crossed with a white-flowered plant. What is the probability of producing a pink-flowered
plant.
50 %
R
R’
R’
RR’
R’R’
R’
RR’
R’R’
7. What cross will produce the most pink-flowered plants? Show a Punnett square to support your answer.
A red-flowered plant crossed with a white-flowered plant.
R
R
R’
RR’
RR’
R’
RR’
RR’