Test: Science and Technology - 2 - UPSC MCQ

The Golden rice was created by transforming rice with two beta-carotene biosynthesis genes:

• psy (phytoene synthase) from daffodil ('Narcissus pseudonarcissus'), which is a variety of maize. Hence statement 1 is not correct.

• crtI (phytoene desaturase) from the soil bacterium Erwinia uredovora.

  Thus, genetic modification of the rice resulted into in the greatest accumulation of total carotenoids and beta‐carotene which is collectively termed provitamin A. Therefore, golden rice is rich source of Vitamin A. It will help to fight against Vitamin A deficiency, which is the leading cause of blindness among children and can also lead to death due to infectious diseases such as measles. Hence statement 2 is correct.

What is 3D Bioprinting?

• 3D Bioprinting is a form of additive manufacturing that uses cells and other biocompatible materials as ―inks‖, also known as bioinks, to print living structures layer-by-layer which mimic the behavior of natural living systems. Hence both statements are correct.

• Bioprinted structures, such as an organ-on-a-chip, can be used to study functions of a human body outside the body (in vitro), in 3D. The geometry of a 3D bioprinted structure is more similar to that of a naturally occurring biological system than an in vitro study performed in 2D and can be more biologically relevant. It‘s used most commonly in the fields of tissue engineering and bioengineering, and materials science. 3D bioprinting is also increasingly used for pharmaceutical development and drug validation, and in the future will be used for medical applications in clinical settings – 3D printed skin grafts, bone grafts, implants, biomedical devices, and even full 3d printed organs are all active topics of bioprinting research.

How does 3D bioprinting work?

• 3D bioprinting starts with a model of a structure, which is recreated layer-by-layer out of a bio-ink either mixed with living cells or seeded with cells after the print is complete. These starting models can come from anywhere – a CT or MRI scan, a computer-generated design (CAD) program, or a file downloaded from the internet.

• That 3D model file is then fed into a slicer – a specialized kind of computer program which analyzes the geometry of the model and generates a series of thin layers, or slices, which form the shape of the original model when stacked vertically. Cura and slices are examples of slicers commonly used in 3D printing. Allevi also has a specialized slicer, optimized specifically for bioprinting, built into our Allevi Bioprint software.

• Once a model is sliced, the slices are transformed into path data, stored as a g-code file, which can be sent to a 3D bioprinter for printing. The bioprinter follows instructions in the g-code file in order, including instructions to control for temperature of the extruders, extrusion pressure, bed plate temperature, crosslinking intensity and frequency, and, of course, the 3D movement path generated by the slicer. Once all of the g-code commands are completed, the print is done and can be cultured or seeded with cells as part of a biostudy.

Lassa fever:

• Lassa fever is one of the hemorrhagic fever viruses like Ebola virus, Marburg virus, and others. Hence, statement 1 is correct.

• It is caused by the Lassa virus, a member of the arenavirus family of viruses.

• Unlike the Ebola virus, Lassa fever is not as contagious from person to person, nor as deadly. Hence, statement 2 is not correct.

• Lassa virus is typically transmitted by the urine or feces of Mastomys rats to humans. Hence, statement 3 is correct.

• Health workers may be infected by direct contact with blood, body fluids, urine, or stool of a patient with Lassa fever.

• Lassa fever occurs primarily in West Africa in areas where these rodents live. Blueprint Priority Diseases of WHO: Worldwide, the number of potential pathogens is very large, while the resources for disease research and development (R&D) is limited. To ensure efforts under WHO‘s R&D Blueprint are focused and productive, a list of diseases and pathogens are prioritized for R&D in public health emergency contexts. A WHO tool distinguishes which diseases pose the greatest public health risk due to their epidemic potential and/or whether there is no or insufficient counter-measures.

  At present, the priority diseases are:

  • COVID-19

  • Crimean-Congo hemorrhagic fever

  • Ebola virus disease and Marburg virus disease

  • Lassa fever

  • Middle East respiratory syndrome coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS)

  • Nipah and henipaviral diseases

  • Rift Valley fever

  • Zika

  • Disease X‖: Disease X represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease. The R&D Blueprint explicitly seeks to enable early cross-cutting R&D preparedness that is also relevant for an unknown ―Disease X‖.

At the end of each period in a periodic table is a noble gas element with a closed valence shell. All the orbitals in the valence shell of the noble gases are completely filled by electrons and it is very difficult to alter this stable arrangement by the addition or removal of electrons. The noble gases thus exhibit very low chemical reactivity.

Noble gases have uses that are derived from their other chemical properties. The very low boiling points and melting points of the noble gases make them useful in the study of matter at extremely low temperatures. Therefore often used for specific industrial processes.

• The low solubility of helium in fluids leads to its admixture with oxygen for breathing by deep-sea divers: because helium does not dissolve in the blood, it does not form bubbles upon decompression (as nitrogen does, leading to the condition known as decompression sickness, or the bends).

• Xenon has been used as an anesthetic; although it is costly, it is non-flammable and readily eliminated from the body.

• Radon is highly radioactive; its only uses have been those that exploit this property (e.g., radiation therapy). (Oganesson is also radioactive, but, since only a few atoms of this element have thus far been observed, its physical and chemical properties cannot be documented.).

• Krypton is used in fluorescent bulbs, flashbulbs, and lasers. Lamps filled with krypton are used at some airports as approach lights since their light can penetrate dense fog unusually well.

• Neon is also used as fog lights. Hence option (d) is the correct answer.

• Chloroplasts: They are green-colored plastids, which comprise green-colored pigments within the plant cell and are called chlorophyll. Hence, statement 1 is correct.

• Chloroplast is an organelle that contains the photosynthetic pigment chlorophyll that captures sunlight and converts it into useful energy, thereby, releasing oxygen from water.

• Chloroplasts are found in all green plants and algae. They are the food producers of plants. These are found in the guard cells located in the leaves of the plants. They contain a high concentration of chlorophyll that traps sunlight. This cell organelle is not present in animal cells. Hence, statement 2 is correct.

• Chloroplast has its own DNA and can reproduce independently, from the rest of the cell. They also produce amino acids and lipids required for the production of chloroplast membrane.

• Functions of Chloroplast: Following are the important chloroplast function:

  • The most important function of the chloroplast is to synthesize food by the process of photosynthesis.

  • Absorbs light energy and converts it into chemical energy.

  • Chloroplast has a structure called chlorophyll which functions by trapping the solar energy and used for the synthesis of food in all green plants.

  • Produces NADPH and molecular oxygen (O2) by photolysis of water.

  • Produces ATP – Adenosine triphosphate by the process of photosynthesis.

  • The carbon dioxide (CO2) obtained from the air is used to generate carbon and sugar during the Calvin Cycle or dark reaction of photosynthesis.

  • Where does the photosynthesis process occur in the plant cell?

  • In all green plants, photosynthesis takes place within the thylakoid membrane of the Chloroplast.

In these regions, the magnetic field is open to interplanetary space, sending solar material

out in a high-speed stream of solar wind i.e., geomagnetic storm.

Coronal holes can last between a few weeks to months thus not a permanent formation. Hence, statement 2 is not correct.

The holes are not a unique phenomenon, appearing throughout the sun’s approximately 11-year solar cycle.

Structure of Nephron

• The mammalian nephron is a long tube-like structure, its length varying from 35–55 mm long. At one end, the tube is closed, folded and expanded, into a double-walled, cuplike structure called the Bowman‘s capsule or renal corpuscular capsule, which encloses a cluster of microscopic blood vessels called the glomerulus. This capsule and glomerulus together constitute the renal corpuscle.

Functions of Nephron

• The primary function of the nephron is removing all waste products including the solid wastes, and other excess water from the blood, converting blood into urine, reabsorption, secretion, and excretion of numerous substances.

• As the blood passes through the glomerulus with high pressure, the small molecules are moved into the glomerular capsules and travel through a winding series of tubules.

• The cell present in each tube absorbs different molecules excluding the glucose, water, and other beneficial molecules which are called ass ultrafiltrate. As the ultrafiltrate molecules travel down the tubules they become more and more hypertonic, which results in more amount of water to be extracted from the ultrafiltrate before it exits the nephrons.

• The blood surrounding the nephron travels back into the body through the renal blood vessels, which are free of toxins and other excess substances. The obtained ultrafiltrate is urine, which travels down via the collecting duct to the bladder, where it will be stored and released through the urethra.

What is a clone?

• A clone is a living organism (such as a plant or animal), which shares the same genetic information as another organism. However, their characteristics can be affected by random mutations which occur in their DNA during development in the womb or by the environment that they grow up in, so, although clones have the same DNA, they may not look the same or behave in the same way.

• While some clones can be found in nature, it is also possible for scientists to create a clone or identical copy of an organism. It is important to understand that a cloned animal is not the same as a genetically modified animal. Hence, statement 1 is correct.

• A cloned animal shares the same DNA as another animal, while a genetically modified animal has had a change made to its DNA, but does not share its DNA with any other animals. Hence, statement 2 is correct.

• Scientists can also use bacteria or viruses to replicate or clone individual DNA sequences that they are interested in. This is known as molecular or DNA cloning.

It is a versatile and efficient tactical transport aircraft which can perform a number of different

missions.

It can routinely operate day as well as night combat missions from desert to maritime

environments. Hence, statement 2 is not correct.

It is a versatile and efficient tactical transport aircraft which can perform a number of different

missions

It can dissolve gold, even though neither of these acids can do so alone. Aqua regia is a highly corrosive, fuming liquid. It is one of the few reagents that are able to dissolve gold and platinum. Hence statement 2 is correct.

• Reverse Osmosis is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semi-permeable membrane.

• Total Dissolved Solids (TDS) in water are some organic and inorganic materials, which include minerals and ions that are dissolved in a particular quantity in water. When water passes through stones, pipes or different surfaces, the particles are absorbed into the water. TDS in water can come from different sources such as minerals in chemicals used for treating water, runoff from the road salts and chemicals or fertilizers from the farms.

• Water that has a TDS level of more than 1000mg/L is unfit for consumption. A high level of TDS in water can lead to a number of health problems. The presence of potassium, sodium, chlorides increases the TDS level in the water. However, the presence of toxic ions such as lead, nitrate, cadmium, and arsenic present in water can lead to a number of serious health problems. This is especially important for children because they are much more sensitive to contaminants because their defence systems have not fully developed. Hence statement 1 is correct.

• Several types of devices are used to improve the aesthetic qualities of drinking water and to remove chemicals. Activated carbon filters are the most common, they are more effective in removing organic chemicals. They are often used to improve taste, smell and appearance. Hence statement 2 is not correct.

• The desalinated water that is demineralized or deionized, is called permeate (or product) water. The water stream that carries the concentrated contaminants that did not pass through the RO membrane is called the reject (or concentrate) stream.

• Statement 1 is not correct: Homo indicates the genus of human beings.

• Statement 2 is correct: Human beings belong to the species sapiens.

• Statement 3 is correct: All human beings belong to kingdom Animalia. All animals belonging to various phyla are assigned to the highest category called Kingdom Animalia in the classification system of animals.

• Nutrient Based Subsidy (NBS) Regime Under the NBS regime – fertilizers are provided to the farmers at subsidized rates based on the nutrients (N, P, K & S) contained in these fertilizers.

• Also, the fertilizers which are fortified with secondary and micronutrients such as

• molybdenum (Mo) and zinc are given additional subsidy. Hence, statement 2 is not

• correct.

• The subsidy on P&K fertilizers is announced by the Government on an annual basis for

• each nutrient on a per kg basis – which are determined taking into account the international and domestic prices of P&K fertilizers, exchange rate, inventory level in the country etc. Hence, statement 1 is not correct.

• NBS policy intends to increase the consumption of P&K fertilizers so that optimum balance

• (N:P:K = 4:2:1) of NPK fertilization is achieved. Hence, statement 3 is not correct.

• This would improve soil health and as a result the yield from the crops would increase, resulting in enhanced income to the farmers.

• Also, as the government expects rational use of fertilizers, this would also ease off the burden of fertilizer subsidy.

• It is being implemented since April 2010 by the Department of Fertilizers, Ministry of Chemicals & Fertilizers.

• The term ̳black hole‘ was coined in the mid-1960s by American physicist John Archibald Wheeler. Blackhole refers to a point in space where the matter is so compressed as to create a gravity field from which even light cannot escape.

• Black-holes were theorized by Albert Einstein in 1915. There is a region of space beyond the black hole called the event horizon. Hence statement 2 is correct.

• This is a "point of no return", beyond which it is impossible to escape the gravitational effects of the black hole.

• Black holes have an intense gravitational field near them because of the large amount of mass they have which is concentrated in a very small volume. Hence statement 1 is correct.

• If one defines the density of a black hole as the ratio of its mass to its volume, then the density decreases as the size of the black hole increases. So the ―density‖ would depend on the size of the black hole. The ―density‖ of black holes left behind by stellar death is much, much higher than that of the earth.

Stars end their lives in two different ways:

• those will mass around the mass of the Sun will end their lives in a gentle way, becoming a planetary nebula and leaving behind a remnant called "white dwarf".

• Stars much more massive than the Sun explode as a supernova leaving behind either a "neutron star" or a "black hole".

So the Sun will never burst and will not become a black hole. Hence statement 3 is not correct.

• The main use of litmus is to test whether a solution is acidic or basic. Light Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F). The neutral litmus paper is purple.

• Lemon Juice and Orange Juice are acidic in nature and thus they turn the Light Blue litmus paper into the red. Vinegar is acidic. White distilled vinegar, the kind best suited for household cleaning, typically has a pH of around 2.5. Hence the correct option is (d)

• Sodium bicarbonate, otherwise known as baking soda, has a pH level, of around 8.4, and it is still alkaline in nature. Human blood has a normal pH range of 7.35 to 7.45. This means that blood is naturally slightly alkaline or basic. Hence both do not have any effect on the Light Blue litmus paper.

• Litmus can also be prepared as an aqueous solution that functions similarly. Under acidic conditions, the solution is red, and under alkaline conditions, the solution is blue.

Statement 1: Correct. The Indian Rhinoceros, also known as the Greater One-horned Rhinoceros, is the only species of rhino found in India.

Statement 2: Incorrect. The Indian Rhinoceros is not the largest of all the rhino species. The White Rhino is the largest species, followed by the Black Rhino and the Javan Rhino.

What is DNA? DNA, or deoxyribonucleic acid, is the fundamental building block for an individual's entire genetic makeup. It is a component of virtually every cell in the human body. Further, a person's DNA is the same in every cell. For example, the DNA in a man's blood is the same as the DNA in his skin cells, semen, and saliva.

DNA is a powerful tool because each person's DNA is different from every other individual's, except for identical twins. Because of that difference, DNA collected from a crime scene can either link a suspect to the evidence or eliminate a suspect, similar to the use of fingerprints. It also can identify a victim through DNA from relatives, even when nobody can be found. And when evidence from one crime scene is compared with evidence from another, those crime scenes can be linked to the same perpetrator locally, statewide, and across the Nation.

Where is DNA contained in the Human body?

DNA is contained in blood, semen, skin cells, tissue, organs, muscle, brain cells, bone, teeth, hair, saliva, mucus, perspiration, fingernails, urine, feces, etc. Hence option (d) is the correct answer.

• The rusting of iron can be prevented by painting, oiling, greasing, galvanizing, chrome plating, anodizing or making alloys.

• Galvanization is a method of protecting steel and iron from rusting by coating them with a thin layer of zinc. The galvanized article is protected against rusting even if the zinc coating is broken.

• Alloying is a very good method of improving the properties of a metal. We can get the desired properties by this method.

• Chrome plating (less commonly chromium plating), often referred to simply as chrome, is a technique of electroplating a thin layer of chromium onto a metal object. The chromed layer can be decorative, provide corrosion resistance, ease cleaning procedures, or increase surface hardness.

• Anodising is an electrolytic process for producing thick oxide coatings, usually on aluminium and its alloys. The oxide layer is typically 5 to 30μm in thickness and is used to give improved surface resistance to wear and corrosion, or as a decorative layer. Hence the correct option is ©.

It is based on the ideology of women for women, as in rural areas, women feel more comfortable sharing their queries with a female herself. Hence, Statement 2 is correct.

• Proton, neutron, and electron are tiny particles that makeup atoms. The neutrino is also a tiny elementary particle, but it is not part of the atom. Such particles are also found to exist in

• nature. Hence statement 1 is correct.

• Neutrino has a very tiny mass and no charge. It interacts very weakly with other matter particles. So weakly that every second trillion of neutrinos fall on us and pass through our bodies unnoticed.

• Neutrinos come from the sun (solar neutrinos) and other stars, cosmic rays that come from beyond the solar system, and from the Big Bang from which our Universe originated. They can also be produced in the lab. Hence statement 3 is correct.

• The INO (India based Neutrino Observatory) will study atmospheric neutrinos only. Solar neutrinos have much lower energy than the detector can detect. INO Project is aimed at building a world-class underground laboratory with a rock cover to conduct basic research on the neutrino.

• The Tata Institute of Fundamental Research is the nodal institution. The observatory is to be built jointly with the Department of Atomic Energy and the Department of Science and Technology. The observatory will be located underground so as to provide adequate shielding to the neutrino detector from cosmic background radiation.

• The operation of INO will have no release of radioactive or toxic substances. It is not a weapons laboratory and will have no strategic or defence applications.

• They are the second most abundant particle in the universe after particles of light called photons. Hence statement 2 is not correct.

Uses:

DNA fingerprinting most often has been used in court cases and legal matters. It can:

• Physically connect a piece of evidence to a person or rule out someone as a suspect.

• Show who your parents, siblings, and other relatives may be.

• Identify a dead body that‘s too old or damaged to be recognizable.

• DNA fingerprinting is extremely accurate. Most countries now keep DNA records on file in much the same way police keep copies of actual fingerprints.

• For criminal identification. Hence, option 1 is correct.

• To resolve disputes of maternity/paternity. Hence, option 2 is correct.

• To identify mutilated remains. Hence, option 3 is correct.

• In cases of exchange of babies in a hospital ward. Hence, option 4 is correct.

• In forensic wildlife. Hence, option 5 is correct.

It also has medical uses. It can:

• Match tissues of organ donors with those of people who need transplants.

• Identify diseases that are passed down through your family.

• Help find cures for those diseases, called hereditary conditions.

• A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapour gas-discharge lamp that uses fluorescence to produce visible light.

• An electric current in the gas excites mercury vapour, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. Hence option (a) is the correct answer.

• Astatine is a radioactive element of the halogen series: a decay product of uranium and thorium that occurs naturally in minute amounts and is artificially produced by bombarding bismuth with alpha particles. There are currently no uses for astatine outside of research.

• Cinnabar is a toxic mercury sulphide mineral with a chemical composition of HgS. It is the only important ore of mercury. It has a bright red colour that has caused people to use it as a pigment, and carve it into jewellery and ornaments for thousands of years in many parts of the world.

• Diphtheria: It is an infection caused by the bacterium Corynebacterium diphtheriae. Hence option 1 is correct.

• Tetanus: It is an infection caused by bacteria called Clostridium tetani. Hence option 2 is correct.

• Leprosy is an infectious disease caused by a bacillus, Mycobacterium leprae. The disease mainly affects the skin, the peripheral nerves, mucosa of the upper respiratory tract, and the eyes. It is curable with multidrug therapy (MDT). It is likely transmitted via droplets, from the nose and mouth, during close and frequent contact with untreated cases. India officially eliminated leprosy in 2005, reducing its prevalence rate to 0.72 per 10,000 people at national level but still hosts highest patients of leprosy in the world. Hence option 3 is correct.

• Whooping cough, also called pertussis, is a serious respiratory infection caused by a type of bacteria called Bordetella pertussis. It can cause serious illness in babies, children, teens, and adults. Some other diseases which are caused by bacteria are: Cholera, typhoid, tuberculosis. Plague, and Anthrax etc. Hence option 4 is correct.

• A bacteriophage is a type of virus that infects bacteria. The word "bacteriophage" literally means "bacteria eater," because bacteriophages destroy their host cells. All bacteriophages are composed of a nucleic acid molecule that is surrounded by a protein structure. A bacteriophage attaches itself to a susceptible bacterium and infects the host cell. Hence option (c) is the correct answer.

• Following infection, the bacteriophage hijacks the bacterium's cellular machinery to prevent it from producing bacterial components and instead forces the cell to produce viral components. Eventually, new bacteriophages assemble and burst out of the bacterium in a process called lysis. Bacteriophages occasionally remove a portion of their host cells' bacterial DNA during the infection process and then transfer this DNA into the genome of new host cells. This process is known as transduction.

• Since their discovery, bacteriophages have been considered to be potential antibacterial therapeutics for the treatment of various infectious diseases in humans. In recent times, the rapid rise of multi-drug resistant bacteria worldwide has led to a renewed interest in phage therapy as a possible alternative to antibiotics or, at least, a supplementary approach for the treatment of some bacterial infections.

• Furthermore, bacteriophage-based vaccination is emerging as one of the most promising preventive strategies.

• Bulk Drug Parks are being promoted through the production-linked incentive (PLI) schemes. Hence, statement 1 is correct.

• The government plans to implement a PLI system with 10-20% output incentives for the agrochemical sector to create an end-to-end manufacturing ecosystem through the growth of clusters.

• The PLI scheme was conceived to scale up domestic manufacturing capability, accompanied by higher import substitution and employment generation. Hence, statement 2 is correct.

FSO is a line-of-sight technology that uses lasers to provide optical bandwidth connections. Currently, FSO is capable of up to 2.5 Gbps of data, voice and video communications through the air, allowing optical connectivity without requiring a fibre-optic cable or securing spectrum licenses. Hence statement 2 is correct.

This contrasts with using solids such as optical fibre cable. FSO communications can provide high data rates in Gbits/s ranges through the atmosphere for ranges from a few hundreds of meters to a few kilometres.

FSO links include the following:

• chip-to-chip communication,

• indoor infrared (IR) or VLC,

• interbuilding communication, and

• free-space laser communications including airborne, spaceborne, and deep space missions.

Free-space point-to-point optical links can be implemented using infrared laser light, although low-data-rate communication over short distances is possible using LEDs, Infrared Data Association (IrDA) technology is a very simple form of free-space optical communications. Hence statement 3 is correct.

There are several transmission windows between 780 nm and 1600 nm wavelength range. These windows are very suitable for FSO operation due to its low attenuation, as well as the availability of high-quality transmitter and detector components.

• The halogens are a series of non-metal elements in the periodic table consisting of five chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). The recently artificially created element 117, Tennessine (Ts), may also be a halogen. In the modern IUPAC nomenclature, this group is known as group 17.

• The name "halogen" means "salt-producing". When halogens react with metals, they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide.

• The group of halogens is the only periodic table group that contains elements in three of the main states of matter at standard temperature and pressure. All of the halogens form acids when bonded to hydrogen. Most halogens are typically produced from minerals or salts.

• The middle halogens—chlorine, bromine, and iodine—are often used as disinfectants in the water-purification system. Organobromides are the most important class of flame retardants, while elemental halogens are dangerous and can be lethally toxic.

• During springtime in the polar regions, unique photochemistry converts inert halide salt ions (e.g. Br−) into reactive halogen species (e.g. Br atoms and BrO) that deplete ozone in the boundary layer to near-zero levels. Hence the correct option is (d)

• Of the five states, the matter can be in, the Bose-Einstein condensate is perhaps the most mysterious. Gases, liquids, solids, and plasmas were all well studied for decades, if not centuries; Bose- Einstein condensates weren't created in the laboratory until the 1990s.

• A Bose-Einstein condensate is a group of atoms cooled to within a hair of absolute zero. When they reach that temperature the atoms are hardly moving relative to each other; they have almost no free energy to do so. At that point, the atoms begin to clump together and enter the same energy states. They become identical, from a physical point of view, and the whole group starts behaving as though it were a single atom.

• This state was first predicted, generally, in 1924–1925 by Albert Einstein following and crediting a pioneering paper by Satyendra Nath Bose on the new field now known as quantum statistics. One application for BEC is for the building of so-called atom lasers, which could have applications ranging from atomic-scale lithography to measurement and detection of gravitational fields. Hence the correct option is (a).

• Respiration in aquatic organisms: Since the amount of dissolved oxygen is fairly low compared to the amount of oxygen in the air, the rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms. Fishes take in water through their mouths and force it past the gills where the dissolved oxygen is taken up by the blood. Hence, statement 1 is correct and 2 is not correct.

• Terrestrial organisms use oxygen in the atmosphere for respiration. This oxygen is absorbed by different organs in different animals. All these organs have a structure that increases the surface area which is in contact with the oxygen-rich atmosphere. Since the exchange of oxygen and carbon dioxide has to take place across this surface, this surface is very fine and delicate. In order to protect this surface, it is usually placed within the body, so there have to be passages that will take air to this area.

• The World Puzzle Federation is an organization of legal entities interested in puzzles. Hence, statement 1 is not correct.

• Prasanna Seshadri has won India's first silver medal after 11 years of trying at the World Puzzle Championship (WPC).

• The objects of the federation are to supervise the World Puzzle Championship (WPC), World Sudoku Championship (WSC) and other WPF events. Hence, statement 2 is correct.

• The WPC gold this year went to Japan’s Ken Endo.