Microbes are not responsible for __________.

• A. decomposition of organic matter
• B. fermentation of dairy products
• C. nitrogen fixation in soil
• D. the formation of volcanic rocks

Answer: (D)

Verified step by step guidance

1. Understand the role of microbes in various natural and industrial processes. Microbes are living organisms such as bacteria, fungi, and archaea that perform many biochemical activities.
2. Review the processes listed: decomposition of organic matter, fermentation of dairy products, and nitrogen fixation in soil. All these are biological processes where microbes play a crucial role.
3. Decomposition of organic matter involves microbes breaking down dead material into simpler substances, recycling nutrients in ecosystems.
4. Fermentation of dairy products is carried out by specific bacteria and yeasts that convert sugars into acids or alcohol, essential in making yogurt, cheese, and other products.
5. Nitrogen fixation in soil is performed by certain bacteria that convert atmospheric nitrogen into forms plants can use, a key step in the nitrogen cycle. In contrast, the formation of volcanic rocks is a geological process involving molten rock cooling and solidifying, which is not influenced by microbial activity.