In the soil there are parts of the biological substances called __________.
Dust
Understanding Biological Substances in Soil
Soil is a complex mixture containing various components, including minerals, water, air, and organic matter. The question asks about the parts of biological substances found in the soil.
Analyzing the Options
Let's look at the provided options and determine which one best fits the description of biological substances in soil:
- Dust: Dust in soil can include fine particles of minerals, but it can also contain fine organic matter, which comes from decomposed biological substances.
- Mineral: Minerals are inorganic naturally occurring solids with a defined chemical composition. They are a key part of soil, but they are not biological substances.
- Rock: Rocks are also inorganic and form the parent material of soil. They are not biological substances.
- Dam: A dam is a barrier constructed to hold back water. It is not a component of soil.
Identifying Biological Substances in Soil
Biological substances in soil are primarily derived from living organisms, such as plants, animals, and microbes, and their remains. When these organisms die, they decompose and become part of the soil's organic matter.
Considering the options provided and focusing on the term "biological substances," the most appropriate answer among the choices, especially if "dust" is interpreted broadly to include finely divided organic material, is "Dust." While scientists often use terms like 'organic matter' or 'humus' for biological substances in soil, in a simplified context, very fine particles of decomposed biological material could be considered part of the soil's dust component.
Conclusion
Based on the analysis of the options and the focus on biological substances, the presence of fine organic matter, which is biological, can be part of the soil's dust component. Therefore, among the given choices, 'Dust' is identified as containing parts of biological substances.
| Component | Description | Biological Substance? |
|---|---|---|
| Dust (can contain) | Fine particles (mineral and/or organic) | Yes (if organic) |
| Mineral | Inorganic solid | No |
| Rock | Inorganic solid (parent material) | No |
| Dam | Man-made structure | No |
Revision Table: Soil Components
| Component Type | Examples | Origin |
|---|---|---|
| Minerals | Sand, Silt, Clay particles | Weathered rocks and minerals |
| Organic Matter | Humus, plant and animal remains | Decomposition of living organisms |
| Water | Soil moisture | Precipitation, irrigation |
| Air | Gases like oxygen, nitrogen | Atmosphere (fills pore spaces) |
Additional Information: Organic Matter in Soil
The biological substances in soil are collectively known as soil organic matter (SOM). SOM is crucial for soil health and fertility. It includes:
- Living organisms: Bacteria, fungi, insects, worms, plant roots, etc.
- Fresh residues: Undecayed plant and animal remains.
- Decomposing organic matter: Partially decomposed residues.
- Humus: Stable, highly decomposed organic matter that is resistant to further breakdown.
Soil organic matter improves soil structure, increases water retention, provides nutrients for plants, and supports a diverse soil ecosystem. While very fine organic particles could contribute to the "dust" fraction of soil, the term organic matter is the standard scientific term for biological substances in soil.
Important Questions from Conservation efforts: India and World
The UN’s Sustainable Development Goal 6 aims to ______.
What are the two variables whose relationship is given by the environmental Kuznets curve?
Which of the following Sustainable Development Goals (SDG) seeks to ‘Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss’?
Which of the following Sustainable Development Goals ensures availability and sustainable management of water and sanitation for all?
_________, the world’s first sailing boat made entirely from plastic waste, aims to raise people’s awareness of plastic pollution in oceans.
