Soils and Natural Vegetation of the World - Practice Test 4

Attempt the quiz above first, then review every question with its correct answer and a short explanation below.

1. Q1.Which of the following agricultural practices helps best in retaining soil moisture and suppressing weeds?

   • A.Ploughing
   • B.Mulching✓ Correct Answer
   • C.Deforestation
   • D.Grazing

   Explanation: Mulching involves covering the soil surface with organic or synthetic material to reduce evaporation, moderate temperature, and suppress weed growth.

2. Q2.The 'Downs' are temperate grasslands found in which country?

   • A.United Kingdom
   • B.Australia✓ Correct Answer
   • C.USA
   • D.South Africa

   Explanation: The Downs are the fertile temperate grasslands located in the Murray-Darling basin of Australia.

3. Q3.Buttress roots, which provide structural support to tall trees, are a characteristic feature of:

   • A.Tropical Rainforests✓ Correct Answer
   • B.Taiga
   • C.Tundra
   • D.Desert Scrub

   Explanation: In tropical rainforests, trees grow very tall to reach sunlight, and large buttress roots help support them in the shallow, wet soil.

4. Q4.Which soil type is formed by the process of 'Calcification' in dry grasslands?

   • A.Pedocals✓ Correct Answer
   • B.Pedalfers
   • C.Laterite
   • D.Podzol

   Explanation: Calcification occurs in dry climates where evaporation exceeds precipitation, leading to the accumulation of calcium carbonate (lime) in the soil, forming Pedocals.

5. Q5.The Atacama Desert, known as one of the driest places on Earth, is located in:

   • A.North Africa
   • B.South America✓ Correct Answer
   • C.Australia
   • D.Central Asia

   Explanation: The Atacama Desert is located in South America, west of the Andes Mountains, covering parts of Chile and Peru.

6. Q6.Loam soil is considered ideal for gardening because it is a mixture of:

   • A.Sand and Gravel only
   • B.Clay and Silt only
   • C.Sand, Silt, and Clay✓ Correct Answer
   • D.Rocks and Humus

   Explanation: Loam is a balanced soil mixture of approximately 40% sand, 40% silt, and 20% clay, providing good drainage and nutrient retention.

7. Q7.Which of the following regions is famous for the cultivation of citrus fruits like oranges and lemons?

   • A.Equatorial Region
   • B.Mediterranean Region✓ Correct Answer
   • C.Tundra Region
   • D.Savanna Region

   Explanation: The Mediterranean region's climate (wet winters, sunny summers) is perfectly suited for citrus orchards and viticulture (grapes).

8. Q8.What is the primary role of 'Gypsum' when added to soil?

   • A.To increase acidity
   • B.To treat saline/alkaline soil✓ Correct Answer
   • C.To kill pests
   • D.To darken soil color

   Explanation: Gypsum (Calcium Sulfate) is used to reclaim alkali soils by replacing exchangeable sodium with calcium, improving soil structure.

9. Q9.The 'Manchurian Plain' is an extensive grassland area located in:

   • A.China✓ Correct Answer
   • B.Mongolia
   • C.Russia
   • D.Japan

   Explanation: The Manchurian Plain is a large fertile plain located in Northeast China, known for its rich black soil and agriculture.

10. Q10.Which term refers to the layer of loose, heterogeneous superficial deposits covering solid rock?

    • A.Bedrock
    • B.Regolith✓ Correct Answer
    • C.Core
    • D.Mantle

    Explanation: Regolith describes the layer of loose, rocky material covering bedrock, which eventually weathers to form soil.

11. Q11.Rubber trees (Hevea brasiliensis) are native to which biome?

    • A.Tropical Rainforest✓ Correct Answer
    • B.Temperate Deciduous
    • C.Coniferous Forest
    • D.Savanna

    Explanation: The natural rubber tree is native to the Amazon rainforest (Tropical Rainforest biome) and requires a hot, humid climate.

12. Q12.Contour Ploughing is a method used to:

    • A.Increase water evaporation
    • B.Prevent soil erosion on slopes✓ Correct Answer
    • C.Flatten mountains
    • D.Grow rice in deserts

    Explanation: Contour ploughing involves ploughing along the contours (lines of equal elevation) of a slope to create water breaks that reduce erosion.

13. Q13.The 'Cork Oak' tree, used to make wine stoppers, is primarily found in:

    • A.Portugal and Spain✓ Correct Answer
    • B.India and China
    • C.Canada and USA
    • D.Brazil and Peru

    Explanation: Cork Oak is native to the Mediterranean region, with Portugal producing about 50% of the world's cork supply.

14. Q14.Gleization is a soil formation process associated with:

    • A.Deserts
    • B.Waterlogged, anaerobic conditions✓ Correct Answer
    • C.Volcanic eruptions
    • D.Wind erosion

    Explanation: Gleization occurs in poorly drained, waterlogged soils (like Tundra or swamps) where lack of oxygen leads to the reduction of iron, giving the soil a grey-blue color.

15. Q15.Which of the following is a 'Halophyte'?

    • A.Cactus
    • B.Mangrove✓ Correct Answer
    • C.Pine
    • D.Oak

    Explanation: Halophytes are salt-tolerant plants. Mangroves grow in saline coastal waters and are a classic example.

16. Q16.In the context of vegetation, what is the 'Canopy Layer'?

    • A.The forest floor
    • B.The main continuous layer of foliage in a forest✓ Correct Answer
    • C.The tallest trees sticking out above the rest
    • D.The underground root system

    Explanation: The canopy is the roof of the forest formed by the crowns of dominant trees, intercepting most of the sunlight.

17. Q17.World Soil Day is observed annually on:

    • A.June 5
    • B.December 5✓ Correct Answer
    • C.April 22
    • D.September 16

    Explanation: World Soil Day is held annually on December 5th to focus attention on the importance of healthy soil and advocating for the sustainable management of soil resources.

18. Q18.Which biome is characterized by 'Sclerophyllous' vegetation (hard, leathery, evergreen leaves)?

    • A.Mediterranean✓ Correct Answer
    • B.Tropical Rainforest
    • C.Taiga
    • D.Tundra

    Explanation: Sclerophyllous vegetation is adapted to the Mediterranean climate's long, dry summers by having leaves that reduce water loss.

19. Q19.What is 'Social Forestry'?

    • A.Forestry managed by the government strictly for timber
    • B.Management of forests for the benefit of local communities✓ Correct Answer
    • C.Private forestry for profit only
    • D.Cutting down forests for housing

    Explanation: Social Forestry involves the management and protection of forests and afforestation on barren lands with the purpose of helping environmental, social, and rural development.

20. Q20.Khaki-colored soil found in semi-arid regions is often associated with:

    • A.High Humus
    • B.Sierozem✓ Correct Answer
    • C.Laterite
    • D.Peat

    Explanation: Sierozem (or Grey Desert Soil) is a light-colored, calcium-rich soil found in cool to temperate arid regions (steppes/deserts).