Test: Forests Our Lifeline - Class 7 MCQ

Kerosene is derived from petroleum and is a combustible hydro-carbon in liquid state. It is not derived from forests and so is not a forest product.

Forest products are materials that are derived from forests and forestry either for direct consumption or for commercial use. Gum, plywood and sealing wax are all obtained from forests for different purposes and so are categorized as forest products.

Microorganisms act upon the dead plants to produce humus the increase the fertility of soil.

The correct answer is d) All of the above.

Explanation:

• Stopping dust storms: Trees and plants act as windbreakers, reducing the speed of the wind, which helps prevent dust storms.
• Preventing soil erosion: The roots of trees and plants hold the soil together, preventing it from being washed away by rain or blown away by wind.
• Balancing oxygen and carbon dioxide: Trees absorb carbon dioxide and release oxygen through photosynthesis, helping to maintain a balance in the atmosphere.

Thus, trees and plants provide all these important benefits to the environment.

mushrooms and other micro-organisms feed on dead plant and animal tissues, playing a significant role in decomposing organic matter and recycling nutrients in the ecosystem. They do not feed on living animals, sunlight, or use water as a primary nutrient source. 

Humus is found in the top layer of the soil.

Wooden door, windows and chair are made of timber obtained from forest while polythene is manmade product.

• Furniture: Made from wood, which is a direct product of trees.
• Medicines: Many are derived from plant extracts and compounds.
• Petrol: Not obtained directly from plants. It is a fossil fuel formed from ancient organic matter, including both plants and animals, after millions of years under heat and pressure.
• Paper: Produced from wood pulp, directly sourced from trees.

Petrol is the correct answer, as it is not directly obtained from plants but through geological processes over time.

Plants convert CO₂ into O₂ during photosynthesis. Exchange of gases takes place through stomata.