Science & Technology GK Questions with Answers – Page 20

Safety Integrity Level is a scale of four grades used for safety related electronic systems, and level four is the most demanding, meaning the probability of a dangerous undetected failure is designed to be the lowest of all.

It is the research, design and standards wing of Indian Railways, has its headquarters at Lucknow, and developed Kavach in partnership with Indian manufacturers, first under the name Train Collision Avoidance System.

Kavach is an electronic safety system that acts on a moving train when its driver does not: it applies the brakes if a signal at danger is being approached without braking, holds a train back from passing a red signal, and keeps two locomotives fitted with the system from closing…

The Department of Biotechnology was created in 1986 under the Ministry of Science and Technology to give the subject a separate home, and it supports institutions, fellowships and national facilities; the Review Committee on Genetic Manipulation also works under it.

The two polypeptide chains of the hormone are made in genetically engineered bacteria and then joined by disulphide bonds, giving insulin identical to the human hormone, which ended the dependence on insulin extracted from the pancreas of cattle and pigs and the allergy that sometimes followed.

Rhizobium lives in symbiosis in the root nodules of pulses and fixes atmospheric nitrogen into a form the plant can use, which enriches the soil and reduces the need for nitrogen fertiliser.

A single plant cell retains the capacity to divide and differentiate into every tissue and so to regenerate a whole plant, which is why an explant grown on a sterile nutrient medium can form callus and then complete plantlets.

Plant breeding is the deliberate improvement of crops by choosing parents with desirable characters, crossing them, selecting among the progeny and multiplying the best lines; the high yielding wheat and rice varieties of the Green Revolution came from it, and modern breeding is often combined with tissue culture and marker…

Working under the Ministry of Environment, Forest and Climate Change, it is the apex committee under the rules of 1989 framed under the Environment (Protection) Act, 1986, and no genetically engineered organism may be released into the environment or used on a large scale without its clearance.

Golden rice was engineered to make beta carotene, the precursor from which the body forms vitamin A, in the edible part of the grain, and the pigment gives the rice its golden colour; the aim was to reduce night blindness among populations living mainly on rice.

He devised the polymerase chain reaction, which copies a selected stretch of DNA millions of times through repeated cycles of heating and cooling, using the heat resistant Taq polymerase, and he received the Nobel Prize in Chemistry for it.

Approved in 2002, it is the only genetically modified crop cleared for commercial cultivation by Indian farmers, and it is grown for fibre rather than as food.

The cry genes of Bt cotton come from Bacillus thuringiensis, a soil bacterium that forms crystal protein during sporulation; the protein is inactive as eaten but becomes a toxin in the alkaline gut of the bollworm, which is why the plant resists the pest.

Kudankulam in the Tirunelveli district of Tamil Nadu uses pressurised water reactors of the Russian VVER type, supplied under an agreement signed with the Soviet Union in 1988 and carried forward by Russia.

The Jaduguda mine lies in the Singhbhum belt of Jharkhand and has been worked by the Uranium Corporation of India Limited, a public sector company set up in 1967, since the late nineteen sixties; it was the first uranium mine in the country.

On 11 May 1998 India tested three nuclear devices at Pokhran under Operation Shakti, followed by two more on 13 May, and the day was declared National Technology Day to mark that achievement along with the test flight of the Trishul missile and the first flight of the Hansa aircraft…

The test was carried out in the desert at Pokhran in Rajasthan on 18 May 1974 and was described by India as a peaceful nuclear explosion; Raja Ramanna led the team.

The second stage uses the plutonium 239 recovered from the spent fuel of the first stage as the fuel of a fast breeder reactor, with a blanket of thorium around the core that is converted into uranium 233; a breeder produces more fissile material than it burns, which is how…

Apsara went critical at Trombay near Mumbai on 4 August 1956 and was the first nuclear research reactor not only in India but in the whole of Asia; the CIRUS reactor of 1960 and the Dhruva reactor of 1985 were built at the same site, which is today the Bhabha…

Bhabha founded the Tata Institute of Fundamental Research in 1945, became the first chairman of the Atomic Energy Commission in 1948, drew up the three stage plan built around India's thorium, and led the establishment at Trombay that was renamed the Bhabha Atomic Research Centre after his death in 1966.