Which of the following products of biotechnology can be used as a fuel in place of petrol?

Analyze the question: The question asks which product of biotechnology can replace petrol as a fuel. The key phrase is "product of biotechnology," meaning something made by living organisms (such as yeast or bacteria) through biological processes.

Explain the concept: Biotechnology uses living organisms or their enzymes to make useful products. A classic example is fermentation, where yeast converts sugars (from sugarcane, cassava, maize, or molasses) into ethanol:

C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (catalyzed by zymase enzyme in yeast)

The ethanol produced is called bioethanol. It can be used alone or blended with petrol (called "gasohol") to run engines. Brazil has done this for decades, and Nigeria has also promoted ethanol-petrol blends.

Check each option:

• A. Butane: A hydrocarbon from petroleum and natural gas, used as cooking/lighter gas. It is not a biotechnology product.
• B. Ethanol: Produced by fermentation, a biotechnology process. It burns well and can be used as a petrol substitute or additive. ✔
• C. Ethene: An alkene obtained mainly by cracking petroleum. It is used to make polythene, not as a fuel replacement for petrol.
• D. Propanol: An alcohol, but it is not the typical fermentation product used as a fuel.

Answer: The correct option is B. Ethanol.

Tip: When you see "biotechnology" or "fermentation" with "fuel," think ethanol. Remember: Sugar + yeast → ethanol + carbon dioxide. Also remember that "gasohol" means petrol blended with ethanol.