Question

3. Cystic fibrosis (CF) is an autosomal recessive disorder (cc) and is one of the most common life-shortening genetic diseases. In the United States, 1 in 4,000 children are born with CF. Symptoms of cystic fibrous include the production of salty sweat and thickened mucus in the lining of the lungs and air passages. The thickened mucus obstructs airways and promotes the growth of disease-causing bacteria in the lungs. Most individuals with cystic fibrous die in their 20s and 30s from lung failure. The molecular basis of CF is now understood. People that have CF produce an abnormal form of a chloride ion channel found in cell membranes (CFTR protein) and as a result chloride ions can not cross the membrane. Normally sodium ions follow the chloride and this creates a solute gradient for water to follow. The formation of the salty sweat and thickened mucus characteristic of CF is due to the defective chloride channel. Problem: Allen and Diane have just married and plan to have children in the future. Both had relatives that died from cystic fibrosis, so they both took a test that shows that Allen carries the allele, but Diane does not. A. What is the genotype of Allen? B. What is the genotype of Diane? C. Complete the Punnett Square. D. What are the chances that their child might inherit this disease?.

Answer 1

1. C - normal cftr gene .

c - mutated cftr gene .

A. Genotype Of Allen is Cc.

B. Genotype Of Diane is CC.

C.

Allen/diane	C	C
C	CC	CC
c	Cc	Cc

CC - normal

Cc - carrier of cystic fibrosis .

cc - cystic fibrosis patient.

D. From the punett square 0 number of their children will have cystic fibrosis .

2. Huntington is autosomal dominant

H - normal

h - Huntington’s disease affected .

Since mark father is heterozygous so - Hh.

father - Hh

mother - HH

	H	h
H	HH	Hh
H	HH	Hh.

Since from the above punett square , there will be 50% of chance of getting Huntington disease in mark .