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Is it a good practice to remove grass and small plants that are growing in an open, unused field? Give a reason to support your answer.

No, because the soil surface is covered by plants. Their roots connect the soil particles and hold them in place. It prevents soil erosion,... View Article

How can a farmer convert acidic soil to neutral soil?

It is possible to convert acidic soil into neutral soil by adding lime to the soil. Lime is alkaline and neutralizes the acidity of the soil... View Article

Which of the following situations – ‘A’ or ‘B’ – is advantageous for the absorption of water and minerals? Why? Situation ‘A’: Growth and branching of roots in the C-horizon. Situation ‘B’: Growth and branching of roots in A and B horizons.

Situation ‘B’ is advantageous to plants because A and B-horizons are rich in water, minerals and humus. This layer is rich in... View Article

Read the following statements and give the appropriate terms for each of them. (a) The process of breakdown of rocks by the action of wind, water, sunlight. (b) Removal of topsoil during heavy rains or strong winds. (c) Accumulation of wastes in the soil generated by human activity which alter the features of the soil. (d) The process of movement of water into deeper layers of soil.

(a) Weathering The scenes of the world are continuously mutating. Sun, rain, frost, and wind are breaking down even the most solid of the rocks... View Article

The components of loamy soil are , and __.

sand, clay and slit Loamy soil is a mixture of sand, clay and silt. Besides these particles, the loamy soil contains humus in it. This... View Article

The soil has particles of different sizes. Arrange the words given below in increasing order of their particle size. (Rock, Clay, Sand, Gravel, Silt)

The words according to increasing order of their particle size are, Clay < Slit < Sand < Gravel < Rock Soil is usually referred to... View Article

Read the following statements with reference to the soil. i) Weathering is a very fast process of soil formation. ii) Percolation of water is faster in sandy soils. iii) Loamy soil contains only sand and clay. iv) Topsoil contains the maximum amount of humus. Choose the correct statements from the above. (a) (ii) and (iv) (b) (i) and (iii) (c) (ii) and (iii) (d) (i) and (ii)

a) (ii) and (iv) Statements (ii) and (iv) are correct. Options (i) and (iii) are wrong. (i) Weathering is a slow process of soil formation... View Article

Soil conservation measures are mainly aimed at protecting which of the following? (a) Plants (b) Topsoil (c) Subsoil (d) Soil organisms

b) Top soil Topsoil is nutrients making and also rich in humus. It is fertile to grow plants. The topsoil is the topmost layer of the soil. It... View Article

Availability of water and minerals in the soil for maximum absorption by roots is in the – (a) B-horizon (b) C-horizon (c) A-horizon (d) surface of soil

c) A-horizon A-horizon is also known as topsoil. This layer is basically porous, soft, and also can retain water. It contains the maximum... View Article

The microorganisms present in the soil require moisture (water) and nutrients for growth and survival. Choose from the options below the habitat (place) where the soil has plenty of water and nutrients. (a) Desert (b) Forest (c) Open field (d) Cricket ground

(b) Forest In forests, there will be a lot of trees which hold the soil and prevents soil from erosion. Humus makes the soil fertile and... View Article

Think and suggest some ways to minimise waste and pollutants at their source, taking your home as an example.

To minimize waste and pollutants at their source the following measures can be taken: We should avoid use of plastic bags by using bags made up... View Article

Describe various steps of cleaning wastewater in a wastewater treatment plant.

Wastewater is passed through bar screens. Large objects like rags, sticks, cans, plastic packets, napkins are removed. Water then goes to a grit... View Article

A very _____ number of our people defecate in the open. It may cause _ pollution and soil pollution. Both the surface water and _ water get polluted. _ water is the source for wells, tubewells and _. Thus it becomes the most common route for _ borne diseases like _____, dysentery, etc.

A very large number of our people defecate in the open. It may cause water pollution and soil pollution. Both the surface... View Article

The terms sewage, sewers and sewerage are interlinked with each other. Can you explain, how?

Wastewater released by home, industry, hospital etc. are called sewage. The small and big pipes that takes away sewage is called sewers. The... View Article

What are the different types of inorganic and organic impurities generally present in sewage?

Different types of inorganic and organic impurities generally present in sewage are as follows: Inorganic impurities: nitrate, phosphate, metals... View Article

A mixture (x) in water contains suspended solids, organic impurities, inorganic impurities (a), nutrients (b), disease-causing bacteria and other microbes. Give names for (x), (a) and (b)?

Sewage is actually the wastewater that is released from houses, hospitals, industries, offices and other sources. It also includes the rainwater... View Article

Three statements are provided here which define the terms – (a) sludge (b) sewage and (c) wastewater. Pick out the correct definition for each of these terms. (a) The settled solids that are removed in wastewater treatment with a scraper. (b) Water from the kitchen used for washing dishes. (c) Wastewater released from homes, industries, hospitals and other public buildings.

a) The settled solids that are removed in wastewater treatment with a scraper. Sludge - It is the collection of settled solids that are removed... View Article

Given below is a jumbled sequence of the processes involved in a wastewater treatment plant. Arrange them in their correct sequence. (a) Sludge is scraped out and skimmer removes the floating grease. (b) Water is made to settle in a large tank with a slope in the middle. (c) Large objects like plastic bags are removed by passing wastewater through bar screens. (d) Sand, grit and pebbles are made to settle by decreasing the speed of incoming wastewater. (e) Wastewater enters a grit and sand removal tank.

The major aim of wastewater treatment is to remove as much of the suspended solids as possible before the remaining water, called effluent, is... View Article

Why should we not throw (a) used tea leaves into the sink? (b) cooking oil and fats down the drain?

a) We should not throw used tea leaves into sink as it chokes the drain and do not allow free flow of oxygen which hampers the degradation... View Article

A man travelling in a train threw an empty packet of food on the platform. Do you think this is a proper waste disposal method? Elaborate.

This is not a proper waste disposal method. We should throw the empty packets into proper dustbins. Generally, these empty food packets are made... View Article

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