Many elements are found in living organisms either free or in the form of compounds. One of the following is not found in living organisms.

Options

A. Silicon
B. Magnesium
C. Iron
D. Sodium

Answer

A

Explanation

Various mineral elements present in living organisms include major elements carbon (c), nitrogen (N), oxygen, hydrogen, phosphorous, calcium, magnesium, sodium, potassium and chlorine and trace elements iodine, iron, manganese, cobalt, copper, zinc, molybdenum, boron etc.