Question

According to Oparin and Haldane, during the course of origin of life what was the correct sequence of substances which appeared on earth?

• A. methane, polysaccharides, monosaccharides
• B. amino acids, ammonia, nucleic acids
• C. protein, amino acids, nucleic acids
• D. ammonia, amino acids, protein

Answer 1

The correct option is D ammonia, amino acids, protein

According to Oparin and Haldane, the correct sequence of the substances which appeared on the Earth during the course of origin of life are as follows:

1. The primitive atmosphere contained gases like ammonia, methane, and water vapour. These inorganic compounds reacted to form the simple organic micromolecules like monosaccharides (simple sugars), amino acids, fatty acids and nucleotides.

2. Formation of macromolecules: The simple organic micromolecules combined to form large complex organic molecules in the ocean water.
- Amino acids joined to form polypeptides and proteins.
- Simple sugar units combined to form polysaccharides.
- Glycerol and fatty acids are esterified to form fats.
- Nucleotides polymerize to form nucleic acids.

Ammonia was present earlier which individually reacted with other compounds to form monomers like amino acids and later the polymers like proteins are formed.
So, the option that has the correct sequence of substances that appeared during the course of origin of life is option 'd'.