Question

According to abiogenic origin of life, proposed by Oparin ____ was the simplest organic compound to arise.
A. Organic acids
B. Hydrocarbons
C. Carbohydrates
D. Proteins

Answer 1

Oparin and Haldane said that the first life originated from non-living things at some point of time in the very long past when conditions on earth would have been very different. Hence the origin of life was first by abiogenesis and then biogenesis ever since.

Complete answer: According to Oparin, the primitive earth had no oxygen in free gaseous form but only as bound in water and metallic oxides on the surface of rocks, hence it was reducing the atmosphere. There were eight steps in the transformation of the early environment and origin of life. These steps or phases were atomic phase, formation of simple organic molecules, formation of organic molecules, prebiotic stage, nucleic acid or genes or virus like stage prokaryotes stage, autotrophic prokaryote stage and eukaryote stage.
The interaction of chemicals in the atmosphere, hydrosphere and lithosphere led to the formation of various organic molecules and energy for this came from heat, lightening, radiation, gravitational forces, etc.
First organic molecule thing formed in the atmosphere was methane and lastly the polymers of protein polysaccharides etc.
Hot water with these organic molecules on the earth surface was called hot dilute soup by Haldane and Darwin. They also referred to the then earth as a warm little pond. This was the prebiotic soup.
According to the abiogenic origin of life, proposed by Oparin, hydrocarbon was the simplest organic compound to arise.
So, the correct answer is “Option B”.

Note: The Oparin and Haldane theory was experimentally proved by Urey and Miller in 1952. They performed a simulation experiment made in spark-discharge apparatus with H2, NH3 and CH4 in ratio of 2:1:2 connected to the flask with boiling water on one hand and condenser on the other hand.