A
Cotton
B
Hair
C
Spider silk
D
Hoof
Correct answer: (a) Cotton
Explanation
- A
Cotton
(a) Cotton. Cotton fibre is almost pure cellulose, not protein. That is the official ‘NOT a protein’ key.
- B
Hair
(b) Hair. Keratin, a fibrous protein.
- C
Spider silk
(c) Spider silk. Fibroin protein.
- D
Hoof
(d) Hoof. Keratin protein, like horn and nail.
Summary. Official key is (a) Cotton. Cotton is cellulose; hair, spider silk and hoof are proteins (keratin/fibroin). Honour the stored letter (a).
Same topic · past papers
UPPSC has asked this before
These previous-year questions sit on the same topic. Open one to practise the earlier ask.