This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Human identification, Subject name: Forensic Medicine
The medullary index of a human hair is 
Select and explain. 
A. 0.2, B. 0.4, C. 0.5, D. 0.6
A: 0.2
Answer: A: 0.2 
Explanation: Human hair Animal hair Fine thin Coarse & thick Cuticular scales are sho, not continuous Cuticular scales are large, step like projections Coex thick (4-10 times as broad as medulla) Coex thin Pigment more towards the periphery Pigment more towards the medulla Medulla thin & fragmented, sometimes absent Medulla broad, continuous & always present. Medullary index <0.3 Medullary index > 0.5 Precipitin test specific for human Precipitin test specific for animal