Minimalist IAS
← Science & Environment
English हिंदी

Test yourself

Curiosity

Class 8 · 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 · The Invisible Living World: Beyond Our Naked Eye

Prelims 2021 · Q22

Consider the following kinds of organisms:

  1. 1.Copepods
  2. 2.Cyanobacteria
  3. 3.Diatoms
  4. 4.Foraminifera

Which of the above are primary producers in the food chains of oceans?

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

UPSC's answer: (b)

NCERT answers it: Class 12 Biology, Ch 11 (Organisms and Populations); Class 8 Curiosity, Ch 2 (The Invisible Living World: Beyond Our Naked Eye).

How to solve it with NCERT: Class 12 Biology, ch 11: cyanobacteria photosynthesise, and copepods live as parasites on fish, so they are consumers. Class 8 Curiosity, ch 2: diatoms are microalgae that make their own food using sunlight. So 2 and 3 are producers. Answer (b).

Hindi version: UPSC's official question paper (2021), question 22 ↗

Prelims 2021 · Q69

Consider the following:

  1. 1.Bacteria
  2. 2.Fungi
  3. 3.Virus

Which of the above can be cultured in artificial/synthetic medium?

  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: (a)

NCERT answers it: Class 8 Curiosity, Ch 2 (The Invisible Living World: Beyond Our Naked Eye); Class 12 Biology, Ch 8 (Microbes in Human Welfare).

Class 12 Biology, ch 8 shows colonies of bacteria and of fungi growing in petri dishes. Class 8 Curiosity, ch 2: viruses multiply only after they enter a living cell, so they can't grow on an artificial medium. Answer (a).

Hindi version: UPSC's official question paper (2021), question 69 ↗

Ch 8 · Nature of Matter: Elements, Compounds, and Mixtures

Prelims 2016 · Q86

In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index?

  1. 1.Carbon dioxide
  2. 2.Carbon monoxide
  3. 3.Nitrogen dioxide
  4. 4.Sulfur dioxide
  5. 5.Methane

Select the correct answer using the code given below.

  1. (a)1, 2 and 3 only
  2. (b)2, 3 and 4 only
  3. (c)1, 4 and 5 only
  4. (d)1, 2, 3, 4 and 5
Show answer

UPSC's answer: (b)

NCERT answers it: Class 8 Curiosity, Ch 8 (Nature of Matter: Elements, Compounds, and Mixtures).

How to solve it with NCERT: Class 8 Curiosity, ch 8: the major air pollutants are particulate matter, carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide, and the Air Quality Index describes air quality. Carbon dioxide and methane are not on that list. Answer (b).

Beyond NCERT: India's National Air Quality Index (CPCB) uses eight pollutants: PM10, PM2.5, nitrogen dioxide, sulphur dioxide, carbon monoxide, ozone, ammonia and lead. Carbon dioxide and methane are not among them. Source: CPCB, 'About National Air Quality Index' (cpcb.nic.in)

Hindi version: UPSC's official question paper (2016), question 86 ↗

Ch 13 · Our Home: Earth, a Unique Life Sustaining Planet

Prelims 2016 · Q97

With reference to the Agreement at the UNFCCC Meeting in Paris in 2015, which of the following statements is/are correct?

  1. 1.The Agreement was signed by all the member countries of the UN and it will go into effect in 2017.
  2. 2.The Agreement aims to limit the greenhouse gas emissions so that the rise in average global temperature by the end of this century does not exceed 2 °C or even 1.5 °C above pre-industrial levels.
  3. 3.Developed countries acknowledged their historical responsibility in global warming and committed to donate $ 1000 billion a year from 2020 to help developing countries to cope with climate change.

Select the correct answer using the code given below.

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

UPSC's answer: (b)

NCERT answers it: Class 8 Curiosity, Ch 13 (Our Home: Earth, a Unique Life Sustaining Planet).

The one fact NCERT doesn't give: Developed countries' climate-finance goal was $100 billion a year by 2020 — not $1000 billion.

Class 8 Curiosity, ch 13: the Paris Agreement set a goal to limit global warming to below 1.5 °C — statement 2. With the fact, 3 is false. Only option (b) has 2 without 3. Answer (b).

Beyond NCERT: the Agreement came into force in November 2016, not 2017, and countries join it one by one by ratifying it. So statement 1 is false too. Source: UN Treaty Collection, Chapter XXVII-7-d (Paris Agreement), treaties.un.org

Hindi version: UPSC's official question paper (2016), question 97 ↗

← Back to the books

Spotted an error? Tell us — we fix it and record the change here.

NCERT textbooks are published by the National Council of Educational Research and Training (NCERT). Every file comes from NCERT's own website; a full book is joined into one PDF on the reader's device. Minimalist IAS does not store or edit any NCERT file.

Previous-year questions are from UPSC's question papers and answer keys (final keys; for 2026, the provisional key) published on upsc.gov.in.

Minimalist IAS is not affiliated with NCERT or UPSC. Books by other publishers are named for reference only.

NCERT can move or replace a file at any time. We re-check every link each month; if one breaks, tell us.