Science and Technology (Part-I)

Total Questions: 50

41. To meet its rapidly growing energy demand, some opine that India should pursue research and development on thorium as the future fuel of nuclear energy. In this context, what advantage does thorium hold over uranium? [2012-1]

1. Thorium is far more abundant in nature than uranium.

2. On the basis of per unit mass of mined mineral, thorium can generate more energy compared to natural uranium.

3. Thorium produces less harmful waste compared to uranium.

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

Correct Answer: (d) 1, 2 and 3

Solution:Thorium fuel generates no new bomb-usable material in the waste profile; the waste consists of the radioisotope Uranium-233, or U233, which is virtually impossible to weaponize/ Thorium fuel will generate more energy per unit of mass than uranium fuel by a factor of approximately 30. Thorium is four times more abundant in nature than uranium, and is widely distributed throughout the Earth's crust. All statements in this question are correct.

42. Indiaisanimportantmemberofthe International Thermonuclear Experimental Reactor'. If this experiment succeeds, what is the immediate advantage for India? [2016-1]

(a) It can use thorium in place of uranium for power generation
(b) It can attain a global role in satellite navigation
(c) It can drastically improve the efficiency of its fission reactors in power generation
(d) It can build fusion reactors for power generation

Correct Answer: (d) It can build fusion reactors for power generation

Solution:(i) The ITER (International Thermonuclear Experimental Reactor) project aims to make the long-awaited transition from experimental studies of plasma physics to full-scale electricity-producing fusion power stations.

(ii) As such project started in 2006, to find whether Nuclear fusion can be a source of energy and electricity in future.

Hence (d) is the apt choice.

43. In India, why are some nuclear reactors kept under "IAEA Safeguards" while others are not? [2020-1]

(a) Some use uranium and others use thorium
(b) Some use imported uranium and others use domestic supplies
(c) Some are operated by foreign enterprises and others are operated by domestic enterprises
(d) Some are State-owned and others are privately-owned

Correct Answer: (b) Some use imported uranium and others use domestic supplies

Solution:As per the India-US Civilian Nuclear Deal, India can maintain 2-types of nuclear reactors. Certain reactors, in which we are using the domestic fuel, India can keep them outside the purview of IAEA.

However, the reactors in which we are using imported fuel, they will be mandatorily under the IAEA inspection.

There are at present 22 operational reactors of, which 14 are under the International Atomic Energy Agency (IAEA) safeguards as these use imported fuel.

44. Which of the following professional(s) are more likely to run the risk of a permanent change in their cell's DNA? [1996]

1. Researchers using Carbon 14 isotope

2. X-ray technician

3. Coal miner

4. Dyer and painter

Select the correct answer by using the codes given below:

(a) 2 alone
(b) 1, 2 and 3
(c) 1, 2 and 4
(d) 1, 3 and 4

Correct Answer: (c) 1, 2 and 4

Solution:X-Raytechnique, C and Dyer technique is very important technique for permanent change in DNA. But in coal miner, C amount is very very less. So, there is no risk of change in DNA.

45. Which one of the following techniques can be used to establish the paternity of a child? [1997]

(a) Protein analysis
(b) Chromosome counting
(c) Quantitative analysis of DNA
(d) DNA finger printing

Correct Answer: (d) DNA finger printing

Solution:DNAfingerprintingtechnology istheprocessofestablishing the biological paternal relationship between individual and his alleged child on the analysis of sample cells taken from each of them.

DNA finger printing can solve cases of rape murder etc.

46. Assertion (A): Insect resistant transgenic cotton has been produced by inserting Bt gene. [1999]

Reason (R): The Bt gene is derived from a bacterium.

(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

Correct Answer: (a) Both A and R are true and R is the correct explanation of A

Solution:Assertion (A) states that insect-resistant transgenic cotton has been produced by inserting the Bt gene. Bt stands for Bacillus thuringiensis, which is a bacterium that produces a protein toxic to certain insect pests. By inserting the Bt gene into cotton plants, they can produce this insecticidal protein and become resistant to specific insect pests.

Reason (R) states that the Bt gene is derived from a bacterium. This is true as the Bt gene is sourced from Bacillus thuringiensis, a naturally occurring soil bacterium that produces the insecticidal protein. The gene responsible for producing this protein can be isolated and inserted into the genome of other plants, such as cotton, to confer insect resistance.

Therefore, both Assertion (A) and Reason (R) are true, and Reason (R) provides the correct explanation for Assertion (A).

47. Assertion (A): Dolly was the first cloned mammal. [1999]

Reason (R): Dolly was produced by in vitro fertilization.

(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

Correct Answer: (c) A is true but R is false

Solution:A is true, but R is false. Dolly, indeed, was the first cloned mammal, which makes assertion (A) true. However, the reason (R), stating that Dolly was produced by in vitro fertilization, is false.

Dolly was produced using a technique called Somatic Cell Nuclear Transfer (SCNT). In this process, the nucleus of an egg cell was removed and replaced with the nucleus of a somatic (body) cell from another adult individual. Then, the egg was stimulated to divide, forming an embryo that was identical to the organism that donated the somatic cell. The embryo was then implanted into a surrogate mother.

In vitro fertilization is a different process wherein an egg is fertilised by sperm outside the body. Therefore, this is not the technique used to produce Dolly.

48. Assertion (A): "DNA finger printing" has become a powerful tool to establish paternity and identity of criminals in rape and assault cases. [2000]

Reason (R): Trace evidences such as hairs, saliva and dried semen are adequate for DNA analysis.

(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

Correct Answer: (a) Both A and R are true and R is the correct explanation of A

Solution:DNA finger printing is the technique which identify paternity and criminals in rape cases, by the help of any tissue sample, hair, saliva or dried semen.

49. Insect-resistant cotton plants have been genetically engineered by inserting a gene from a/an : [2000]

(a) virus
(b) bacterium
(c) insect
(d) plant

Correct Answer: (b) bacterium

Solution:Insect resistant cotton plants have been genetically engineered by inserting a gene from bacterium Bacillus thuringiensis.

50. Hybridoma technology is a new biotechnological approach for commercial production of : [2000]

(a) monoclonal antibodies
(b) interferon
(c) antibiotics
(d) alcohol

Correct Answer: (a) monoclonal antibodies

Solution:Hybridoma technology is used to commercially production of monoclonal antibodies. The monoclonal antibodies are protective protein produced by the clone of single immune cell.

« Previous 1 2 3 45