UPSC 2019 Previous Year GK Questions with Answers

The correct answer is D, vacuoles full of cell sap. A large central vacuole filled with sap presses the cytoplasm against the cell wall, keeping the cell firm, or turgid.

In a mature plant cell the central vacuole can take up 50 to 90% of the cell's volume. Its membrane, the tonoplast, controls what enters it, and the sap holds water, sugars, salts, pigments and wastes. When the vacuole is full, water pressure inside pushes outward on the wall; this turgor pressure keeps leaves spread out and soft stems upright. When the plant loses water, vacuoles shrink and the plant wilts.

A is wrong: ribosomes are tiny particles that make proteins; they give no shape or firmness.

B is wrong: mitochondria release energy through respiration; they are not concerned with turgidity.

C is wrong: the Golgi apparatus packages and secretes materials, including those for the cell wall, but it does not keep the cell turgid.

Exam tip: turgidity = central vacuole (turgor pressure); its membrane = tonoplast; animal cells have small or no vacuoles.

The correct answer is C, apical meristem. Apical meristem sits at the growing tips of stems and roots, and its dividing cells make them longer.

Meristems are groups of cells that keep dividing throughout a plant's life. The shoot apex and root apex hold apical meristems, so a plant grows in length from its tips; this is primary growth. In the root the tip is shielded by a root cap as it pushes through soil. Lateral meristem (vascular cambium and cork cambium) adds girth instead, and intercalary meristem lengthens internodes and leaf bases in grasses and bamboo.

A is wrong: lateral meristem increases the thickness of stems and roots, not their length.

B is wrong: intercalary meristem works at the base of internodes and leaves, mainly in grasses; it does not lengthen roots.

D is wrong: secondary growth, by cambium, increases girth; growth in length is primary growth.

Exam tip: apical = length (tips); lateral = girth (cambium); intercalary = base of internodes (grasses, regrowth after grazing).

The correct answer is D, Ribosomes. Ribosomes stuck on the outer surface of the endoplasmic reticulum give it a grainy, rough look under the electron microscope.

The endoplasmic reticulum is a network of membrane tubes and sacs in the cytoplasm. The part carrying ribosomes is the rough ER, and it is busy making proteins, especially those to be secreted or placed in membranes. The part without ribosomes is the smooth ER, which makes lipids and steroid hormones and helps detoxify drugs in liver cells. Cells that secrete a lot of protein, such as pancreatic cells, have plenty of RER.

A is wrong: centrioles are paired cylinders near the nucleus that help in cell division; they are not on the ER.

B is wrong: plastids such as chloroplasts are large separate organelles of plant cells.

C is wrong: lysosomes are free membrane sacs of digestive enzymes, not particles fixed on the ER.

Exam tip: RER = ribosomes + protein synthesis; SER = no ribosomes + lipid synthesis and detoxification.

The correct answer is D, The cell will lose water. A medium more concentrated than the cell is hypertonic, so water leaves the cell by osmosis.

In osmosis water moves across a selectively permeable membrane from the side with fewer dissolved particles to the side with more. If the outside solution is stronger, water flows out and the cell shrinks; in a plant cell the cytoplasm pulls away from the wall, which is called plasmolysis. This is why salted raw mango pieces give out water and why sprinkling salt on a garden leech shrivels it.

A is wrong: a cell gains water only when the outside medium is weaker, that is hypotonic.

B is wrong: losing some water does not by itself kill the cell; a plasmolysed plant cell recovers when put back in water.

C is wrong: no net change happens only in an isotonic medium of equal concentration.

Exam tip: hypertonic outside = cell shrinks (plasmolysis); hypotonic outside = cell swells; isotonic = no change.

The correct answer is A, Bacteria contain cytoplasm but viruses do not. A bacterium is a living cell filled with cytoplasm, while a virus is only genetic material inside a protein coat.

Bacteria are prokaryotic cells: they have a cell wall, a cell membrane, cytoplasm with ribosomes, and a circular DNA, but no nucleus bounded by a membrane and no membrane-bound organelles. Viruses are not cells at all. A virus particle (virion) is DNA or RNA wrapped in a protein capsid, sometimes with an outer envelope taken from the host. It has no cytoplasm, ribosomes or metabolism of its own, so it can multiply only inside a living host cell. This is why antibiotics act on bacteria but not on viruses.

B is wrong: bacteria, being prokaryotes, have no mitochondria.

C is wrong: viruses have no organelles, and bacteria have no mitochondria either.

D is wrong: bacteria do have a cell membrane, and viruses have no cell membrane, only a capsid and sometimes an envelope.

Exam tip: bacteria = prokaryotic cell, no mitochondria, killed by antibiotics; virus = nucleic acid + protein coat, not a cell.

The correct answer is B, 1, 2 and 3. All three subjects sit in the list named against them in the Seventh Schedule.

The Seventh Schedule, read with Article 246, divides law-making powers into three lists. Public health and sanitation, hospitals and dispensaries is entry 6 of the State List, so states run most health services. Citizenship, naturalisation and aliens is entry 17 of the Union List, which is why only Parliament made the Citizenship Act, 1955. Legal, medical and other professions is entry 26 of the Concurrent List, so both Parliament and the states can make laws on them, as with the Advocates Act and the National Medical Commission Act.

A is wrong: pair 1 is correct, but pairs 2 and 3 are correct too.

C is wrong: it leaves out the correct pair 1.

D is wrong: it leaves out the correct pairs 1 and 2.

Exam tip: Seventh Schedule with Article 246; public health = State List, citizenship = Union List, professions = Concurrent List.

The correct answer is B, 1 and 2 only. A short notice question is an urgent oral question taken up only with the Minister's consent, and it is answered after Question Hour, not during it.

Under the Rules of Procedure of the Lok Sabha, a member may ask a question on a matter of urgent public importance with less than the usual ten clear days' notice, stating the reason for urgency. It is admitted only if the Minister concerned agrees to answer it at short notice. Such a question is taken up for oral answer immediately after the questions for oral answer of that day have been disposed of, that is, after Question Hour.

A is wrong: it includes statement 3, but these questions come after Question Hour.

C is wrong: it drops the true statement 1 and keeps the false statement 3.

D is wrong: it keeps statement 3 and leaves out the true statement 2.

Exam tip: starred = oral, unstarred = written, short notice = urgent, under ten days, needs the Minister's consent, taken after Question Hour.

The correct answer is C, World Economic Forum. The Global Competitiveness Report is the World Economic Forum's assessment of how well countries' institutions, policies and markets support productivity and growth.

The World Economic Forum is a Geneva-based not-for-profit foundation, set up by Klaus Schwab in 1971 and known for its annual meeting at Davos, Switzerland. Its Global Competitiveness Report, first brought out in 1979, ranks economies on a Global Competitiveness Index built on pillars such as institutions, infrastructure, macroeconomic stability, health, skills, markets and innovation. The WEF also publishes the Global Gender Gap Report and the Global Risks Report.

A is wrong: the IMF publishes the World Economic Outlook and the Global Financial Stability Report.

B is wrong: UNCTAD publishes the World Investment Report and the Trade and Development Report.

D is wrong: the World Bank published the Doing Business Report and publishes the World Development Report.

Exam tip: WEF = Global Competitiveness, Global Gender Gap and Global Risks reports; IMF = World Economic Outlook.

The correct answer is D, Neither 1 nor 2. A jagir was a temporary, transferable revenue assignment given mainly in lieu of salary for military service, while zamindari rights were hereditary.

Under the mansabdari system, a mansabdar was paid either in cash or through a jagir, the right to collect revenue from a tract of land equal to his salary. The jagir was tied to his military rank, was transferred every few years and was not hereditary, so statement 1 is wrong about judicial and police duties being its basis. Zamindars held hereditary rights over a share of the produce and also had duties beyond revenue collection, such as keeping order and supplying troops to the state. So statement 2 has the hereditary part reversed.

A is wrong because statement 1 misstates both the jagir and the zamindar's role.

B is wrong because jagirs, not zamindari rights, were non-hereditary.

C is wrong because both statements are incorrect.

Exam tip: jagir = salary for military rank, transferable; zamindari = hereditary local right.

The correct answer is A, whatever the change in price, there is absolutely no change in demand. Price elasticity of demand is the percentage change in quantity demanded divided by the percentage change in price. If the elasticity is zero, the numerator is zero: buyers take the same quantity however the price moves. This case is called perfectly inelastic demand and its demand curve is a vertical straight line. Textbooks illustrate it with a life-saving medicine or with salt, goods a household buys in a fixed quantity because there is no substitute and the spending is small. Option B is wrong because a small response to a small price change means elasticity between zero and one, that is inelastic but not zero demand. Option C is wrong because a large response to a small price change is elastic demand, with elasticity greater than one. Option D is wrong because that too describes ordinary inelastic demand, where some change still takes place. Exam tip: elasticity zero is a vertical curve, elasticity infinity a horizontal one, and elasticity one is unitary.

The correct answer is A, 1 and 2 only. The Act of 1813 broke the Company's trade monopoly and asserted the Crown's sovereignty, but left the revenues where they were, so the first two statements stand and the third does not. The Act came at the height of the free trade campaign in Britain: it threw the India trade open to all British merchants, keeping the monopoly only in tea and in the China trade, which was ended by the Charter Act of 1833. It also declared in plain words that the Crown held sovereignty over the Indian territories the Company governed, and it set aside one lakh rupees a year for education and allowed missionaries into India. Statement 3 is wrong because the Company continued to control and spend Indian revenues; Parliament supervised through the Board of Control rather than taking the purse. B and D are wrong because each includes statement 3. C is wrong for the same reason and also drops statement 2. Exam tip: 1813 opened trade except tea and China; 1833 ended the monopoly altogether.

The correct answer is D, neither 1 nor 2. Both statements describe the two offices wrongly, so neither can be accepted. A jagir was an assignment of the land revenue of a tract, given to a mansabdar in place of a cash salary for military and administrative service, not for judicial and police duty; the holder collected the revenue due and kept troops from it. Jagirs were transferable and were shifted every three or four years so that no noble struck roots in one district, and they lapsed to the emperor on the holder's death, so statement 1 is wrong. A zamindar, by contrast, held a hereditary right in the soil of his locality, collected revenue from the peasants and passed on the state's share while keeping a commission called nankar, so the hereditary part of statement 2 is exactly reversed. A, B and C are wrong because each accepts at least one of these two flawed statements. Exam tip: jagir was transferable and not hereditary, zamindari was hereditary and rooted in the locality.

The correct answer is D, the level of mutual trust and harmony in the society. Social capital means the networks, shared norms and trust that let people in a society work together, so it is measured by relationships rather than by things or numbers of people. The idea was popularised by Robert Putnam, who argued that a community rich in trust and civic association gets better government and faster growth because agreements are kept without costly enforcement. Self-help groups, cooperatives and village committees are the everyday form it takes in India. A is wrong because literacy is part of human capital, the skill and knowledge embodied in people. B is wrong because buildings, infrastructure and machines are physical or produced capital. C is wrong because the size of the working age group is the demographic dividend, a matter of population structure. Exam tip: physical capital is what you build, human capital is what you learn, social capital is whom you trust.

The correct answer is A, Baiju Bawra. Baiju, also called Baiju Nayak, was the leading singer at the court of Raja Man Singh Tomar in Gwalior and later served Sultan Bahadur Shah of Gujarat. Raja Man Singh Tomar ruled Gwalior from 1486 to 1516 and is credited with shaping dhrupad, the oldest surviving style of Hindustani classical music. Baiju was a master of dhrupad, and legend makes him a rival of Tansen, a story retold in the 1952 film "Baiju Bawra". Gwalior's link with music continues today through the Tansen Samaroh held there every year. Option B is wrong because Tansen sang at the court of Raja Ramchandra of Rewa and then became one of the nine jewels of Akbar's court. Option C is wrong because Lal Kalawant was a disciple of Tansen who served at the Mughal court. Option D is wrong because Rang Khan Kalawant is not recorded at the courts of Man Singh Tomar or Bahadur Shah. Exam tip: Man Singh Tomar of Gwalior made dhrupad famous; Baiju sang there, and Tansen later shone at Akbar's court.

The correct answer is D, Forest Act 1878. The Indian Forest Act of 1878 created the three classes of reserved, protected and village forests. British interest in Indian forests grew as the railways and shipbuilding needed huge amounts of timber. The Imperial Forest Department was set up in 1864 with Dietrich Brandis as the first Inspector General of Forests, and the first Indian Forest Act followed in 1865. That Act was soon found too weak, so the 1878 Act replaced it, giving the state firm control over forest land and sharply cutting down villagers' customary rights, above all in reserved forests. Its successor, the Indian Forest Act, 1927, kept the same three classes and is still the main forest law. Option A is wrong because 1864 is the year the Forest Department was created, not a classification law. Option B is wrong because the 1865 Act only began state control and did not create the three classes. Option C is wrong because 1866 is not linked with this classification at all. Exam tip: 1864 department, 1865 first Act, 1878 three classes, 1927 Act still in use.

The correct answer is C, Protection of ozone layer. Both treaties were made to save the ozone layer in the stratosphere, which screens out harmful ultraviolet rays. The Vienna Convention for the Protection of the Ozone Layer was adopted in 1985 as a framework agreement. The Montreal Protocol of 1987 put it into action by fixing deadlines to phase out ozone-depleting substances such as chlorofluorocarbons (CFCs) and halons. In 2009 these became the first UN treaties ratified by every country, and 16 September, the day the Protocol was signed, is observed as World Ozone Day. The Kigali Amendment of 2016 extended the Protocol to hydrofluorocarbons (HFCs). Option A is wrong because desertification is handled by the UN Convention to Combat Desertification of 1994. Option B is wrong because the Sustainable Development Goals were adopted by the UN General Assembly in 2015 as part of Agenda 2030. Option D is wrong because climate change falls under the UNFCCC of 1992, with its Kyoto Protocol and Paris Agreement. Exam tip: Vienna 1985 and Montreal 1987 for ozone; Kigali 2016 added HFCs.

The correct answer is B, violet light. Violet has the shortest wavelength in visible light, so glass slows it the most and bends it the most. White light is a mix of seven colours, remembered as VIBGYOR. The refractive index of glass is slightly different for each colour, highest for violet and lowest for red. So when white light passes through a prism, each colour bends through a different angle and the light spreads into a coloured band called a spectrum. This splitting is called dispersion, and Isaac Newton showed it with a glass prism in his experiments of 1666. A rainbow is the same dispersion happening inside raindrops. Option A is wrong because red has the longest wavelength and is bent the least, so it lies at the other end of the spectrum from violet. Option C is wrong because yellow lies in the middle of the spectrum and deviates less than violet. Option D is wrong because blue bends more than yellow but still a little less than violet. Exam tip: red deviates least and violet most; the shorter the wavelength, the bigger the bend.

The correct answer is A, Bauxite, Magnetite, Malachite and Calamine respectively. Each metal here is paired with one of its best-known ores. Bauxite is hydrated aluminium oxide; alumina is refined from it and then broken down by electrolysis in the Hall-Héroult process. Magnetite (Fe3O4) is the magnetic ore of iron, while haematite (Fe2O3) is India's chief iron ore. Malachite is a green basic copper carbonate, though copper pyrites is the main commercial ore of copper. Calamine is zinc carbonate (ZnCO3), and zinc blende (ZnS) is the other main ore of zinc; the Zawar mines of Rajasthan are famous for it. Option B is wrong because it gives aluminium to magnetite and iron to bauxite. Option C is wrong because it runs the list backwards, pairing aluminium with calamine and zinc with bauxite. Option D is wrong because malachite is an ore of copper, not aluminium, and bauxite is not an ore of copper. Exam tip: "B-M-M-C" in order: Bauxite-Al, Magnetite-Fe, Malachite-Cu, Calamine-Zn.

The correct answer is C, 143. The number 235 is the mass number and uranium's atomic number is 92, so the nucleus holds 235 minus 92, that is 143 neutrons. The mass number (A) counts protons and neutrons together, while the atomic number (Z) counts only protons, so neutrons = A − Z. Every uranium atom has 92 protons; its isotopes differ only in the number of neutrons. Uranium-235 makes up only about 0.7% of natural uranium, the rest being mostly U-238 with 146 neutrons. Yet U-235 is the isotope that splits easily when struck by a slow neutron, which is why reactor fuel is "enriched" in it. Option A is wrong because 235 is the total of protons and neutrons, not the neutrons alone. Option B is wrong because 92 is the number of protons, that is the atomic number. Option D is wrong because 51 has no link with this nucleus and is only a distractor. Exam tip: neutrons = mass number minus atomic number; U-235 has 143 and U-238 has 146.

The correct answer is A, whatever the change in price, there is absolutely no change in demand. Elasticity measures how strongly the quantity demanded reacts to price, and zero means no reaction at all. Price elasticity of demand is the percentage change in quantity demanded divided by the percentage change in price. When it is zero, demand is perfectly inelastic and the demand curve is a vertical straight line. Life-saving medicines such as insulin come closest to this, since a patient buys the same dose whatever the price. At the other extreme, perfectly elastic demand, with infinite elasticity, gives a horizontal demand curve. Option B is wrong because any change in demand, however small, means the elasticity is above zero. Option C is wrong because a large response to a small price change means elastic demand, with elasticity greater than one. Option D is wrong because a small response to a large price change is relatively inelastic demand, between zero and one, but still not zero. Exam tip: elasticity zero gives a vertical curve; elasticity infinite gives a horizontal one.