Question

Among six elements forming $98$% of living mass, which is not included?

• A. $P$
• B. $S$
• C. $Cl$
• D. $H$

Answer 1

Answer: (C)

$Cl$

The six most essential elements are carbon, hydrogen, nitrogen, phosphorous, sulfur and oxygen.

Carbon and hydrogen is an important constituent of carbohydrates which is an instant source of energy.

Phosphorous forms an important component of ATP which is known as energy currency of the cell.

Sulfur is an integral part of amino acids like methionine which plays an important role in transcription.

Oxygen is the most abundant element for the living organism. It is used for respiration. The oxygen inhaled supports the oxidation of food and releases energy. It plays an important role in the oxidative phosphorylation occurring in the mitochondria. The process produces energy in form of ATP.

Nitrogen is an important component of the amino acids which is a monomer of protein.

Chlorine is not present in six most essential elements. It helps to main ionic gradient inside the body. It also helps in gaseous exchange by the process of chloride shift.

So, the correct answer is option D.