Q41easy
Which one of the following is used in preparing a natural mosquito repellent?
(a) Congress grass
(b) Elephant grass
(c) Lemongrass
(d) Nut grass
Answer: (c)
UPSC 2021 Science & Tech PYQ Solved
14 Science & Tech questions from UPSC 2021 Prelims GS Paper 1 — solved with answers
14
Questions
57%
Trap Rate
Common Misconception
Top Trap
Q45easyCommon Misconception
Magnetite particles, suspected to cause neurodegenerative problems, are generated as environmental pollutants from which of the following?
1. Brakes of motor vehicles
2. Engines of motor vehicles
3. Microwave stoves within homes
4. Power plants
5. Telephone lines
Select the correct answer using the code given below.
(a) 1, 2, 3 and 5 only
(b) 1, 2 and 4 only
(c) 3, 4 and 5 only
(d) 1, 2, 3, 4 and 5
Answer: (d)
Trap Analysis
This question uses a specific pattern to mislead well-prepared aspirants. The elimination strategy narrows options to two.
Q75moderateAbsolute Qualifier
With reference to recent developments regarding 'Recombinant Vector Vaccines', consider the following statements :
1. Genetic engineering is applied in the development of these vaccines.
2. Bacteria and viruses are used as vectors.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (c)
Trap Analysis
This question uses a specific pattern to mislead well-prepared aspirants. The elimination strategy narrows options to two.
Q76moderatePartial Truth
In the context of hereditary diseases, consider the following statements :
1. Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of egg.
2. A child inherits mitochondrial diseases entirely from mother and not from father.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (c)
Trap Analysis
This question uses a specific pattern to mislead well-prepared aspirants. The elimination strategy narrows options to two.
Q77easy
Bollgard I and Bollgard II technologies are mentioned in the context of
(a) clonal propagation of crop plants
(b) developing genetically modified crop plants
(c) production of plant growth substances
(d) production of biofertilizers
Answer: (b)
Q78moderateCommon Misconception
In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following?
1. Area of the hole in the lid
2. Temperature of the flame
3. Weight of the lid
Select the correct answer using the code given below.
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (d)
Trap Analysis
This question uses a specific pattern to mislead well-prepared aspirants. The elimination strategy narrows options to two.
Q79easy
Consider the following :
1. Bacteria
2. Fungi
3. Virus
Which of the above can be cultured in artificial/synthetic medium?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (a)
Q80moderateCommon Misconception
Consider the following statements :
1. Adenoviruses have single-stranded DNA genomes whereas retroviruses have double-stranded DNA genomes.
2. Common cold is sometime caused by an adenovirus whereas AIDS is caused by a retrovirus.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (b)
Trap Analysis
This question uses a specific pattern to mislead well-prepared aspirants. The elimination strategy narrows options to two.
Q91easy
Water can dissolve more substances than any other liquid because
(a) it is dipolar in nature
(b) it is a good conductor of heat
(c) it has high value of specific heat
(d) it is an oxide of hydrogen
Answer: (a)
Q92moderateCommon Misconception
With reference to street-lighting, how do sodium lamps differ from LED lamps?
1. Sodium lamps produce light in 360 degrees but it is not so in the case of LED lamps.
2. As street-lights, sodium lamps have longer life span than LED lamps.
3. The spectrum of visible light from sodium lamps is almost monochromatic while LED lamps offer significant colour advantages in street-lighting.
Select the correct answer using the code given below.
(a) 3 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (c)
Trap Analysis
This question uses a specific pattern to mislead well-prepared aspirants. The elimination strategy narrows options to two.
Q93easy
The term 'ACE2' is talked about in the context of
(a) genes introduced in the genetically modified plants
(b) development of India's own satellite navigation system
(c) radio collars for wildlife tracking
(d) spread of viral diseases
Answer: (d)
Q94moderateSimilar Sounding
Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics?
(a) Low-density polyethylene
(b) Polycarbonate
(c) Polyethylene terephthalate
(d) Polyvinyl chloride
Answer: (b)
Trap Analysis
This question uses a specific pattern to mislead well-prepared aspirants. The elimination strategy narrows options to two.
Q95moderateDistractor Pairing
'Triclosan', considered harmful when exposed to high levels for a long time, is most likely present in which of the following?
(a) Food preservatives
(b) Fruit-ripening substances
(c) Reused plastic containers
(d) Toiletries
Answer: (d)
Trap Analysis
This question uses a specific pattern to mislead well-prepared aspirants. The elimination strategy narrows options to two.
Q96easy
Which one of the following is a reason why astronomical distances are measured in light-years?
(a) Distances among stellar bodies do not change.
(b) Gravity of stellar bodies does not change.
(c) Light always travels in straight line.
(d) Speed of light is always same.
Answer: (d)