Question

Basic elements of life are

• A. $C,H,O,N$
• B. $C,P,H,S$
• C. $H,O,N,S$
• D. $P,C,O,N$

Answer 1

Answer: (A)

: Protoplasm is made up mainly of $C,H,\text{O},$ and N, which make up 95% by weight of the body. The proportions of various elements in protoplasm is - oxygen (65%), carbon (8%), hydrogen (10%), nitrogen (3%), calcium (2.5%), phosphorous (1.14%), chlorine (0.15%), sulphur (0.16%) and potassium, sodium, magnesium, iodine, iron etc. are in traces.