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Subject:

science-chemistry

Class:

class VII

Key Concepts

clayey, percolation, humus, soil erosion, moisture, absorption, water retention, Loamy

essential questions

1.Why is soil important to all living things?
2. Why do plants grow in soil?
3. What is a healthy soil?
4. How do we classify soils?

Remembering:

  1. Humus and the smallest particles of rock form the: a) A- horizon  b) B- horizon c) C-horizon  d) Bed rock
  2. Which of these has the smallest size of particles: a) sand  b) silt  c) clay  d) gravel
  3. Which type of soil is best for growing cotton: a) sandy  b) clayey c) Loamy  d) sandy- loamy
  4. Which of these do not cause weathering: a) clouds  b) winds  c) flowing water  d) freezing water
  5. Paddy grows best in: a) Clayey soil  b) Loamy soil  c) sandy soil  d) sandy- loamy soil
  6. ____ are soils in which more than half of the parent mineral matter is volcanic ash and appear very dark: a) clayey soil  b) volcanic soil  c) Alluvial soil  d) Clayey soil
  7. Soil contains rock particles and_____ a) Water and air   b) water and plants  c) minerals , organic matter, air and water  d) water, air and plants
  8. Of the four distinct layers or sections of soil profile, organic matter is found in: a) top soil  b) second layer from the top  c) third layer from the top  d) the bottom layer
  9. The topmost soil is: a) soft later  b) porous layer  c) can retain more water  d) all
  10. Soil best suited for cultivation of wheat, rice and sugarcane is a) Alluvial soil  b) laterite  c) mountain soil  d) none
  11. Humus refers to the a) topmost layer  b) bottom layer  c) rotting dead matter in soil  d) None
  12. Clay particles are size: a) More than 0.004mm  b) less than0.04mm c) more than 0.02mm d) less than 0.002 mm
  13. ___does not lead to soil erosion a) deforestation  d) dense vegetation  c) over grazing  d) winds
  14. Khaddar is another name for a) black soil  b) Alluvial soil  c) red soil d) desert soil
  15. Earthworms are called: a) natural decomposers  b) farmer’s enemies  c) farmer’s friends d) plant decomposer
  16. Which layer is formed of decayed organic matter: a) air  b) humus  c) clay  d) minerals
  17. In which of the following agricultural methods different types of crops are grown in a piece of land season after season: a) Monoculture  b) Irrigation  c) crop rotation d) manure
  18. Fungi and bacteria grow mostly in which layer of soil: a) sub soil  b) top soil  c) bed rock  d) all of the above
  19. Which of the following sequences show the correct arrangements of different layers of the soil:  a) Top soil→ subsoil→ bedrock  b) sub soil→ bed rock→ top soil  c) bed rock → top soil → sub soil  d) sub soil → top soil → bed rock
  20. Soil suitable for growing wheat and gram: a) clayey and loamy  b) sandy and clayey  c) sandy and loamy  d) silt and sandy

understanding:

  1. Given formula calculates what aspect of soil: amount of water (ml) / time taken (minutes) a) rain  b) humidity  c) climate  d) percolation
  2. What can be inferred from this statements.

    Statement1: Soil contains air, water, minerals and organic matter.

    a) Soil can support plant and animal life   b) soil cannot support life  c) Soil can only support plant life  d) Soil can support animal life

  3. Based on the given information which is correct about importance of soil to plants: 1) Soil supplies plants with food  2) soil supplies plants with minerals  3) soil supplies plants with air and water  a) only 1  b) Only 2 and 3  c) only 1 and 2  d) 1,2 and 3
  4. Water percolating into the soil collects over: a) A-horizon  b) B-Horizon  c) C-horizon  d) None
  5. Water logging can be expected in soil which is rich in: a) sand  b) clay  c) silt  d) humus
  6. A well developed soil profile is the result of: a) Physical process  b) chemical process c) organic process d) all of the above
  7. Percolation of water is highest in: a) loamy soil  b) clayey soil  c) sandy soil  d) alluvial soil

Application:

  1. ____ we can see profile of soil: a) at the side of steep river bank  b) at the side of raod of hills c) Both of them d) none
  2. Soil is used to make surai and matka: a) loamy soil  b) sandy soil  c) clayey soil  d) none
  3. A fertile agricultural soil appears deep colored at the surface as compared to the soil one meter down. the reason for the color of top soil is due to: a) rich in organic matter b) fertilizer  c) more moisture  d) recent formation

Analysis:

  1. Statement 1: The soil in place A has a very high absorption rate.

         Statement 2: The soil in place A is very good for growing cotton crop.

a) Both Statement 1 and statement 2 are correct. Statement 2 is correct explanation of statement 1

b) Both statement 1 and statement 2 are correct but statement 2 is not the correct explanation for statement 1.

c) Statement1 is correct and statement 2 is false

d) Statement 1 s false and statement 2 is correct.

   2. Statement 1: Percolation rate of water is different in different types of soil.

       Statement 2: The rate of percolation is highest in dry soil as the particles are large in size.

a) Both Statement 1 and statement 2 are correct. Statement 2 is correct explanation of statement 1

b) Both statement 1 and statement 2 are correct but statement 2 is not the correct explanation for statement 1.         c) Statement1 is correct and statement 2 is false

d) Statement 1 s false and statement 2 is correct.

   3. Statement 1: Percolation and absorption rate are inversely related with each other.

       Statement 2: If the water percolation is high then its absorption rate will also be very high.

a) Both Statement 1 and statement 2 are correct. Statement 2 is correct explanation of statement 1

b) Both statement 1 and statement 2 are correct but statement 2 is not the correct explanation for statement 1.

c) Statement1 is correct and statement 2 is false

d) Statement 1 s false and statement 2 is correct.

4.

Evaluation:

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