"Leaf litter decomposes faster than in any other biome and as a result the soil surface is often almost bare. Apart from trees, the vegetation is largely composed of plant forms that reach up into the canopy vicariously, by climbing the trees or growing as epiphytes, rooted on the upper branches of trees." This is the most likely description of
- A.coniferous forest
- B.dry deciduous forest
- C.mangrove forest
- D.tropical rain forest
Correct answer
Explanation
The correct answer is D, tropical rain forest. Constant heat and heavy rain make decomposition fastest there, and climbers and epiphytes are its typical plant forms.
Tropical rain forests lie near the equator, in the Amazon, the Congo basin and South-East Asia, with temperatures around 27°C and rain in every month. In such conditions fungi, bacteria and termites break down fallen leaves within weeks, so little litter builds up and most nutrients are held in the living plants rather than the soil. The tall trees form a dense, layered canopy that shuts out light. To reach that light, lianas climb the trunks, and epiphytes such as orchids, ferns and bromeliads grow on high branches without rooting in the ground.
A is wrong because cold coniferous forests decompose litter slowly and have a thick needle layer. B is wrong because a long dry season slows decay in dry deciduous forests. C is wrong because mangroves grow in salty, waterlogged coastal mud and are known for breathing roots, not epiphytes.
Exam tip: fastest litter decay = tropical rain forest; slowest = tundra and taiga.
Practice Questions
View allWhich one among the following is the northernmost geographical location ?
- A.New Delhi
- B.Kathmandu
- C.Thimphu
- D.Dhaka
Show answer
New Delhi lies at about 28.6° N, a little north of both Kathmandu and Thimphu, even though Nepal and Bhutan lie to the north of most of India.
Read the full explanation →Which of the following is/are the applied forces in mechanical weathering process? 1. Gravitational force 2. Expansion force 3. Force due to water pressure Select the answer using the code given below :
- A.1 only
- B.1 and 2 only
- C.2 and 3 only
- D.1, 2 and 3
Show answer
Mechanical (physical) weathering breaks rocks without changing their chemistry, and all three forces drive it. Gravitational forces act as overburden pressure, load and shearing stress on rocks.
Read the full explanation →According to the Census 2011, the density of population in which one among the following States is the lowest ?
- A.Sikkim
- B.Nagaland
- C.Manipur
- D.Mizoram
Show answer
Census 2011 recorded about 52 persons per sq km in Mizoram, the lowest of the four states given. Mizoram is a hilly, heavily forested state with a small population of about 11 lakh, which keeps its density low.
Read the full explanation →Consider the following statements : 1. The Earth's magnetic field has reversed every few hundred thousand years. 2. When the Earth was created more than 4000 million years ago, there was 54% oxygen and no carbon dioxide. 3. When living organisms originated, they modified the early atmosphere of the Earth. Which of the statements given above is/are correct ?
- A.1 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
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The magnetic field has flipped many times and life changed the early air, but the young Earth had almost no free oxygen.
Read the full explanation →With reference to the current trends in the cultivation of sugarcane in India, consider the following statements : 1. A substantial saving in seed material is made when 'bud chip settlings' are raised in a nursery and transplanted in the main field. 2. When direct planting of setts is done, the germination percentage is better with single-budded setts as compared to setts with many buds. 3. If bad weather conditions prevail when setts are directly planted, single-budded setts have better survival as compared to large setts. 4. Sugarcane can be cultivated using settlings prepared from tissue culture. Which of the statements given above is/are correct?
- A.1 and 2 only
- B.3 only
- C.1 and 4 only
- D.2, 3 and 4 only
Show answer
Bud chip nurseries save seed cane and tissue-culture settlings are used, but single-bud setts do worse than larger setts when planted directly.
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