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Exploration

Class 9 · Science & Environment

Real UPSC Prelims questions from 2016–2026, linked to this book. Try each one first, then open the answer. 2026 answers follow UPSC's provisional answer key.

Ch 2 · Cell: The Building Block of Life

Prelims 2020 · Q47

Which of the following statements are correct regarding the general difference between plant and animal cells?

  1. 1.Plant cells have cellulose cell walls whilst animal cells do not.
  2. 2.Plant cells do not have plasma membrane unlike animal cells which do.
  3. 3.Mature plant cell has one large vacuole whilst animal cell has many small vacuoles.

Select the correct answer using the code given below:

  1. (a)1 and 2 only
  2. (b)2 and 3 only
  3. (c)1 and 3 only
  4. (d)1, 2 and 3
Show answer

UPSC's answer: (c)

NCERT answers it: Class 9 Exploration, Ch 2 (Cell: The Building Block of Life).

Class 9 Exploration, ch 2: the plant cell wall is made mainly of cellulose (1), and every cell has a plasma membrane (so 2 is false). A mature plant cell usually has one large central vacuole (3). Answer (c).

Hindi version: UPSC's official question paper (2020), question 47 ↗

Ch 12 · Patterns in Life: Diversity and Classification

Prelims 2016 · Q22

In which of the following regions of India are you most likely to come across the 'Great Indian Hornbill' in its natural habitat?

  1. (a)Sand deserts of northwest India
  2. (b)Higher Himalayas of Jammu and Kashmir
  3. (c)Salt marshes of western Gujarat
  4. (d)Western Ghats
Show answer

UPSC's answer: (d)

NCERT answers it: Class 9 Exploration, Ch 12 (Patterns in Life: Diversity and Classification).

How to solve it with NCERT: Class 9 Exploration, ch 12: the Great Hornbill is one of four hornbills of Pakke, a forest in Arunachal Pradesh, and these birds nest only in large, old trees. Deserts, the high Himalayas and salt marshes have no such forests. Answer (d).

Hindi version: UPSC's official question paper (2016), question 22 ↗

Prelims 2018 · Q94

In which one of the following States is Pakhui Wildlife Sanctuary located?

  1. (a)Arunachal Pradesh
  2. (b)Manipur
  3. (c)Meghalaya
  4. (d)Nagaland
Show answer

UPSC's answer: (a)

NCERT answers it: Class 9 Exploration, Ch 12 (Patterns in Life: Diversity and Classification).

The one fact NCERT doesn't give: Pakhui and Pakke are two names for the same protected area in East Kameng district of Arunachal Pradesh; it was made a tiger reserve in 2002.

Class 9 Exploration, ch 12: the Pakke Tiger Reserve is a forest in Arunachal Pradesh. Answer (a).

Hindi version: UPSC's official question paper (2018), question 94 ↗

Prelims 2026 · Q23

Which of the following best explain(s) the rationale for protecting mangrove ecosystems in the context of climate resilience?

  1. 1.Mangroves reduce tidal energy and store freshwater, making them ideal sites for paddy cultivation in saline estuarine belts.
  2. 2.Their salt-sensitive roots filter seawater, making mangroves key to converting coastal land into freshwater aquaculture zones.
  3. 3.By withstanding tidal surges and offering biomass resources, mangroves function both as natural bio-shields and livelihood bases for rural communities.

Select the answer using the code given below:

  1. (a)1 only
  2. (b)1 and 2
  3. (c)2 and 3
  4. (d)3 only
Show answer

UPSC's provisional answer: (d)

NCERT answers it: Class 11 India: Physical Environment, Ch 5 (Natural Vegetation); Class 11 Fundamentals of Physical Geography, Ch 6 (Landforms and their Evolution); Class 9 Exploration, Ch 12 (Patterns in Life: Diversity and Classification).

How to solve it with NCERT: Class 11 India: Physical Environment, ch 5: mangroves grow in salt marshes, tidal creeks and estuaries, so they are neither salt-sensitive nor freshwater stores (1, 2 false). Class 11 Fundamentals of Physical Geography, ch 6: mangroves absorb storm and tsunami waves (3). Answer (d).

Hindi version: UPSC's official question paper (2026), question 23 ↗

Ch 13 · Earth as a System: Energy, Matter, and Life

Prelims 2018 · Q65

Which of the following statements best describes "carbon fertilization"?

  1. (a)Increased plant growth due to increased concentration of carbon dioxide in the atmosphere
  2. (b)Increased temperature of Earth due to increased concentration of carbon dioxide in the atmosphere
  3. (c)Increased acidity of oceans as a result of increased concentration of carbon dioxide in the atmosphere
  4. (d)Adaptation of all living beings on Earth to the climate change brought about by the increased concentration of carbon dioxide in the atmosphere
Show answer

UPSC's answer: (a)

NCERT answers it: Class 11 Fundamentals of Physical Geography, Ch 11 (World Climate and Climate Change); Class 9 Exploration, Ch 13 (Earth as a System: Energy, Matter, and Life).

How to solve it with NCERT: Class 11 Fundamentals of Physical Geography, ch 11: forests use CO2 in their growth. Warming (b) is the greenhouse effect, and more acidic sea water (c) is a separate effect, named in Class 9 Exploration, ch 13. 'Fertilization' means growth. Answer (a).

Hindi version: UPSC's official question paper (2018), question 65 ↗

Prelims 2021 · Q27

In case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrient to enter the cycle?

  1. (a)Carbon cycle
  2. (b)Nitrogen cycle
  3. (c)Phosphorus cycle
  4. (d)Sulphur cycle
Show answer

UPSC's answer: (c)

NCERT answers it: Class 12 Biology, Ch 12 (Ecosystem); Class 9 Exploration, Ch 13 (Earth as a System: Energy, Matter, and Life).

The one fact NCERT doesn't give: Phosphorus has no stable gaseous form in the air, unlike carbon, nitrogen and sulphur, so it enters the cycle mainly from rocks as they weather.

Class 12 Biology, ch 12: the carbon cycle's reservoir is the air or water, but the phosphorus cycle's reservoir is the Earth's crust. Class 9 Exploration, ch 13: nitrogen's largest reservoir is the air. Class 10 Contemporary India II, ch 6: sulphur dioxide is one of the gases in polluted air. With the fact, only phosphorus has to come from rocks. Answer (c).

Hindi version: UPSC's official question paper (2021), question 27 ↗

Prelims 2025 · Q29

Consider the following statements:

  1. I.Without the atmosphere, temperature would be well below freezing point everywhere on the Earth's surface.
  2. II.Heat absorbed and trapped by the atmosphere maintains our planet's average temperature.
  3. III.Atmosphere's gases, like carbon dioxide, are particularly good at absorbing and trapping radiation.

Which of the statements given above are correct?

  1. (a)I and III only
  2. (b)I and II only
  3. (c)I, II and III
  4. (d)II and III only
Show answer

UPSC's answer: (c)

NCERT answers it: Class 9 Exploration, Ch 13 (Earth as a System: Energy, Matter, and Life).

How to solve it with NCERT: Class 9 Exploration (Science), ch 13: greenhouse gases such as CO2 absorb the heat the Earth gives off (III), which keeps the planet warm (II). Without the atmosphere the Earth would be too cold for life (I). All three. Answer (c).

Hindi version: UPSC's official question paper (2025), question 29 ↗

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