Question

Cystic fibrosis is characterised by

• A. Increased sodium chloride in sweat
• B. Urine becomes black on exposure to air
• C. Conversion of phenyl aniline into tyrosine
• D. Replacement of glutamic acid by valine

Hint:

Sweat chloride test is used for cystic fibrosis diagnosis due to elevated salt content.

Answer 1

The Correct Option is A

Cystic fibrosis is a genetic disorder affecting exocrine glands causing thick mucus and salty sweat due to defective chloride channels.
This leads to increased sodium chloride concentration in sweat, a key diagnostic marker.

Other options describe different conditions not related to cystic fibrosis.

Hence, cystic fibrosis is characterised by increased sodium chloride in sweat.