Railway GK Questions 2026

Vitamin C, chemically ascorbic acid, is needed to make collagen, the protein that holds tissues together; without it the gums swell and bleed, wounds refuse to heal and the joints ache, and the disease is called scurvy.

Amylase breaks starch into the sugar maltose; a lipase works on fat, and saliva carries no significant lipase, so the statement pairs the right action with the wrong enzyme.

Roots take up nitrogen chiefly as the nitrate ion and to a smaller extent as ammonium; inside the plant the nitrate is reduced and built into amino acids, proteins and nucleic acids.

Carbon dioxide is a trace gas, roughly four hundredths of one per cent of dry air by volume, yet it is the source of all the carbon that photosynthesis fixes into food and the chief gas by which human activity is warming the planet.

Transpiration is the escape of water vapour from a plant, chiefly through the stomata of the leaves, and over a forest or a crop field it returns a large volume of water to the air; together with evaporation from open surfaces it is called evapotranspiration.

About ninety-seven per cent of the water on earth is salt water in the oceans, and of the small freshwater remainder the greater part is locked up as ice in glaciers and the polar ice sheets, with most of what is left held as groundwater.

The very high temperature of a lightning discharge supplies enough energy to break the triple bond of nitrogen, and the atoms join oxygen to give nitric oxide and then nitrogen dioxide, which dissolve in rain as nitrous and nitric acid and reach the soil as nitrate; this is physical or…

Nitrogenase is the enzyme complex, containing molybdenum and iron, that breaks the triple bond of the nitrogen molecule and joins the atoms with hydrogen to make ammonia; it is destroyed by oxygen, which is why a root nodule keeps leghaemoglobin to mop oxygen up.

Dry air is about seventy-eight per cent nitrogen by volume, which makes the atmosphere the great reservoir of the nitrogen cycle, yet the triple bond of the nitrogen molecule is so strong that plants and animals cannot use the gas directly and depend on fixation.

Denitrification is the reduction of nitrate to nitrogen gas, which escapes to the atmosphere and completes the nitrogen cycle; it is carried out by these bacteria in waterlogged soils where oxygen is scarce, and it is the reason farmers lose nitrogen from flooded fields.

Nitrification happens in two stages, and the first is the oxidation of ammonia to nitrite by chemoautotrophic bacteria of the genera Nitrosomonas and Nitrococcus.

Rhizobium is a bacterium that lives in a symbiotic relationship with legumes such as gram, pea, bean, groundnut and arhar, forming nodules on their roots in which it converts nitrogen gas into ammonia using the enzyme nitrogenase; this is why legumes are grown in rotation to restore soil nitrogen.

Phosphorus has no stable gaseous compound in nature, so its reservoir is rock, chiefly the mineral apatite; it enters the soil only through slow weathering, passes through plants and animals, and returns to sediments, which makes it a purely sedimentary cycle and the slowest of the common cycles.

Humus is the dark, formless material left in soil after decomposers have broken down dead leaves, roots and animal remains; it resists further microbial attack and decays only very slowly, which makes it the long term store of carbon and nutrients in soil and a key step in every biogeochemical…

TIFRAC, the Tata Institute of Fundamental Research Automatic Calculator, was the first computer designed and built within India; it was commissioned in 1960 and Jawaharlal Nehru gave it that name.

In his report on the EDVAC design in 1945 John von Neumann set out a computer in which a single memory holds both the program and the data it works on, with a control unit, an arithmetic and logic unit and input and output; that layout is still called the…

Herman Hollerith built an electric tabulating machine that read holes punched in cards, and it cut the time needed to process the United States census of 1890 from years to months.

In 1936 the British mathematician Alan Turing described an abstract machine, now called the Turing machine, that defines what it means for a problem to be computable, and in 1950 he proposed the Turing test, by which a machine is judged intelligent if its answers cannot be told from a…

Intel released the 4004 in 1971, putting a complete central processing unit on a single chip for the first time and beginning the fourth generation of computers along with the age of the personal computer.

The Scottish mathematician John Napier published his work on logarithms in 1614, which turned multiplication into addition, and he then devised a set of numbered rods, Napier’s bones, with which products could be read off mechanically.