INHERITANCE PNNEITSOUARE PRACTICE 1 Cystic fibrosis is an au

INHERITANCE PNNEITSOUARE PRACTICE 1. Cystic fibrosis is an autosomal recessive disorder (f. A male that is healthy meets a woman that is a of cystic fibrosis. They have two children, aboy and a girl The boy is showing the early signs of having cystic fibrosis, but the girl appears to be healthy. a. Complete the Punnett Square for the mother and father below b. What was the probability that the son would inherit cystic fibrosis? c. If they have another child, what are the odds that he/she will be healthy? 2. Carnation flowers follow the pattern of incomplete dominance. a. How could one create all three colors of carnations at a time (red, pink, white)? b. Prove your answer with a Punnett Square. c. What is the phenotype of each parent? d. What is the probability of getting: Heterozygous flowers? White flowers? Homozygous recessive flowers? Homozygous dominant flowers? Chapter 6: Patterns of Inheritance Dog Days of seience

Solution

1. a. Father XY (healthy)   Mother X^cX (carrier)

Offsprings : XX^c XX X^cY XY. As the son shows early signs of the disease, he is X^cY, meaning he has inherited the gene responsible for causing the disease.

b. The is a 100% probability of the the son inheriting cystic fibrosis.

c. If they have another child, and it is a son, then the probability of him having the disease is 50%. If it is a girl, she could be either healthy (XX) or a carrier of the disease. (X^cX)

2. a. The flower\'s colour is homozygous for either red or white. Now when a white homozygous flower pairs with a red homozygous flower, a pink flower is produced. When plants of F1 generation are self pollinated, the phenotypic and genotypic ratio of F2 flowers is 1:2:1 (Red:Pink:White). The following punnett square shows incomplete dominance:

b & c.

Red:Pink:White in the ration 1:2:1

d. White flowers- 25%   Heterogenous flowers- 50% Homogenous dominant flowers- 25%    Homogeneous recessive flowers- 25%

	X	Y
Xc	XXC	XcY
X	XX	XY