Natural Resources Test - 5

Soil erosion can be prevented by good plant cover. The root of plant binds the soil and prevents the soil erosion. Soil erosion occurs faster in bare lands with vegetation.

The process of breaking down large rock particles into small soil particle is called weathering. Wind causes weathering of rocks through abrasion on its surface i.e.,friction due to air pressure

Plants require water for all physiological processes. Water is present in soil as hygroscopic, gravitational and capillary water but water available for plant for absorption is capillary water.

(i)Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. 

(ii) Scraping is a small amount of something that has been obtained by scraping it from a surface.

(iii) Falling of trees means deforestation promote soil erosion.

Top soil is the uppermost fertile soil layer. Top soil contains humus, living organisms and soil particles.

(1) Soil cover and reforestation is a mechanism to protect soil from water loss. Like the protection of an umbrella, soil cover and reforestation protects the soil and the microbes within from the impact of sun heat, rain and wind. It stops the soil surface from sealing, and reduces the amount of precious rainwater that runs off.
(2) Water borne disease is cholera. The bacteria cause cholera.
(3) Soil minerals form the basis of soil. They are produced from rocks (parent material) through the processes of weathering and natural erosion.
(4) Topsoil is the top most layer of soil and is the most fertile because it contains the organic, nutrient-rich materials. 

Overgrazing  deforestation causes loosening of soil particles of top soil which enhances soil erosion 

Lichen releases hydrolytic enzymes which breaks the rocks into small particles

Frost are the ice crystal which get deposited on the rocks which help in contraction of rocks due to which cracks formed on it.

Those substances that can be broken down into simpler forms by action of microbes are called bio-degradable substance, leaves, fruits and vegetables and mud are biodegradable substance. Plastic cannot be broken into simpler forms so, it is an example of non-biodegradable pollutant.

Water pollution is the addition of harmful substance in water that changes its chemical, Physical and biological properties. Water pollution causes eutrophication, pesticidal toxicity and bio magnifications.