UPSC 2021 › Science & Technology

12 questions · 2021 · answers as per the UPSC key

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Topics: Health & Diseases (4)Biotechnology & Genetics (3)Biology (1)Chemistry (1)Energy & Environment (1)Physics (1)Space Technology & Astronomy (1)

Which of the following have species that can establish symbiotic relationship with other organisms?

  1. Cnidarians
  2. Fungi
  3. Protozoa

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
Show answer
Answer: (d) 1, 2 and 3

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
Show answer
Answer: (c) Both 1 and 2

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
Show answer
Answer: (c) Both 1 and 2

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
Show answer
Answer: (b) developing genetically modified crop plants

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
Show answer
Answer: (c) 1 and 3 only

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
Show answer
Answer: (a) 1 and 2 only

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
Show answer
Answer: (b) 2 only

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
Show answer
Answer: (a) it is dipolar in nature

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
Show answer
Answer: (c) 1 and 3 only

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
Show answer
Answer: (d) spread of viral diseases

'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
Show answer
Answer: (d) Toiletries

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.
Show answer
Answer: (d) Speed of light is always same.