Question

Choose the correct option.

About 98% of the mass of every living organism is composed of just six elements, which are carbon, hydrogen, nitrogen, oxygen, ___ and ___.

• A. Sulphur, Magnesium
• B. Magnesium, Sodium.
• C. Calcium, Phosphorus
• D. Phosphorus, Sulphur

Answer 1

The correct option is C

Calcium, Phosphorus

The correct option is C.

Explanation of correct option:

1. Most minerals in the soil can enter plants through their roots, and plants contain more than 60 different elements.
2. These elements are divided into different categories based on their quantities of micronutrients and macronutrients.
3. Macronutrients are generally present in large amounts.
4. The macronutrients include carbon, hydrogen, oxygen, nitrogen, phosphorous, sulfur, potassium, calcium, and magnesium.
5. Micronutrients consist of 7 nutrients: Manganese, Iron, Boron, Zinc, molybdenum, chlorine, and copper. All these elements combined contain less than 1%.
6. 95% of cells consist of carbon, hydrogen, nitrogen, and oxygen because they are structural elements as components of biomolecules.
7. Calcium is found in our bones, and Phosphorus is an essential mineral in our DNA and is required in ATP.
8. Thus six elements that share 98% of the mass of living organisms are carbon, hydrogen, nitrogen, oxygen, Calcium, and phosphorus.

Explanation of incorrect options:

Option A

1. Sulfur content is 0.2% in the living organism.
2. Magnesium is 0.04% in the living organism.

Option B

1. Magnesium is 0.04% in the living organism.
2. Sodium is around 0.0135 - 0.0145% in living organisms.

Option D

1. Sulfur content is 0.2% in the living organism.
2. Phosphorus content is 1.0 - 1.4% in the living organism.

Final Answer:

Calcium and phosphorus, together with carbon, hydrogen, oxygen, and nitrogen, hold about 98 percent of the mass of every living organism.