Daily Quiz: UPSC Prelims Marathon (Science and Technology) – May 28, 2020

The strongest gravitational waves are produced by cataclysmic events such as colliding black holes, supernovae (massive stars exploding at the end of their lifetimes), and colliding neutron stars. Other waves are predicted to be caused by the rotation of neutron stars that are not perfect spheres, and possibly even the remnants of gravitational radiation created by the Big Bang.

The process in which solids directly change to gases is known as sublimation. This occurs when solids absorb enough energy to completely overcome the forces of attraction between them. Dry ice and Camphor are examples of solids that undergo sublimation.

Oxides of Nitrogen.

Statement 1 is incorrect: Nitrogen (N) forms oxides in which nitrogen exhibits each of its positive oxidation numbers from +1 to +5. Nitrous oxide (dinitrogen oxide), N2O, is formed when ammonium nitrate, NH4NO3, is heated. This oxide, which is a colourless gas with a mild, pleasant odour and a sweet taste, is used as an anesthetic for minor operations, especially in dentistry. It is called laughing gas because of its intoxicating effect. It is also widely used as a propellant in aerosol cans of whipped cream.

Statement 2 is correct: Gaseous nitric oxide is the most thermally stable oxide of nitrogen and is also the simplest known thermally stable paramagnetic molecule—i.e., a molecule with an unpaired electron. It is one of the environmental pollutants generated by internal-combustion engines, resulting from the reaction of nitrogen and oxygen in the air during the combustion process.

Styrene is primarily a synthetic chemical. It is also known as vinyl benzene, ethenyl benzene, cinnamene, or phenyl ethylene. It’s a colorless liquid that evaporates easily and has a sweet smell. It often contains other chemicals that give it a sharp, unpleasant smell. It dissolves in some liquids but doesn’t dissolve easily in water. Billions of pounds are produced each year to make products such as rubber, plastic, insulation, fiberglass, pipes, automobile parts, food containers, and carpet backing. Most of these products contain styrene linked together in a long chain (polystyrene) as well as unlinked styrene. Low levels of styrene also occur naturally in a variety of foods such as fruits, vegetables, nuts, beverages, and meats.

Lithium.

Statement 1 is correct: The only chemical elements created at the beginning of our universe were hydrogen, helium and lithium, the three lightest atoms in the periodic table. These elements were formed throughout the universe as a hot gas.

Statement 2 is correct: Lithium makes up a mere 0.0007 percent of the Earth’s crust, according to the Jefferson Lab of USA, and it’s only found locked up in minerals and salts. Those salts have the power to change the brain: Lithium salts were the first drugs approved by the Food and Drug Administration to treat mania and depression, according to the National Institute of Mental Health.

Arthropod.

Statement 1 is incorrect: Arthropods are everywhere and are the largest animal phylum — about 85% of all known animals in the world are part of this class. There are far more species of arthropods than there are species in all the other phylum’s (phyla) combined. They are spiders, insects, centipedes, mites, ticks, lobsters, crabs, shrimp, crayfish, krill, barnacles, scorpions and many, many others.

Statement 2 is incorrect: Arthropods are cold blooded — which means, their body temperature depends on the temperature of the environment surrounding them.

Airborne diseases are those caused by pathogens and transmitted through the air as very small or aerosolized particles. Disease-causing pathogens are organisms that spread from an infected person to another through coughing, talking, and sneezing – even breathing and laughing! According to the U.S. Centers for Disease Control, flu droplets can travel up to six feet away! There are three main types of organisms that can cause airborne diseases, including viruses, bacteria, and fungi. Some examples of airborne diseases include the flu, tuberculosis, and valley fever. SARS-CoV-2, Chickenpox, Diphtheria and the measles can also be caused by airborne pathogens.

Unicellular Organisms.

• Bacteria are tiny, single-celled organismsthat get nutrients from their environments.
• Fungi live as either single-celled organisms or multi-cellular organisms. Single-celled fungi are referred to as yeasts. The vast majority of fungi are multi-cellular. A fungus gets nutrition from plants, food, and animals in damp, warm environments.
• Protozoa are one-celled organisms, like bacteria. But they are bigger than bacteria and contain a nucleus and other cell structures, making them more like plant and animal cells.

Leishmaniasis.

• There are 3 main forms of leishmaniases– visceral (also known as kala-azar, which is and the most serious form of the disease), cutaneous (the most common), and mucocutaneous.
• Leishmaniasis is caused by the protozoan Leishmania parasiteswhich are transmitted by the bite of infected female phlebotomine sandflies.
• The disease affects some of the poorest people on earth, and is associated with malnutrition, population displacement, poor housing, a weak immune system and lack of financial resources.
• Leishmaniasis is linked to environmental changes such as deforestation, building of dams, irrigation schemes, and urbanization.
• An estimated 700 000 to 1 million new cases aoccur annually.
• Only a small fraction of those infected by Leishmania parasites will eventually develop the disease.

Campylobacter species.

Statement 1 is correct: The burden of food-borne diseases, including Campylobacteriosis, is substantial: every year almost 1 in 10 people fall ill and 33 million of healthy life years are lost. Food-borne diseases can be severe, especially for young children. Diarrhoeal diseases are the most common illnesses resulting from unsafe food, with 550 million people falling ill yearly (including 220 million children under the age of 5 years). Campylobacter is 1 of the 4 key global causes of diarrhoeal diseases. It is considered to be the most common bacterial cause of human gastroenteritis in the world.

Statement 2 is correct: Campylobacter species can be killed by heat and thoroughly cooking food. To prevent Campylobacter infections, make sure to follow basic food hygiene practices when preparing food.