Science and Technology Quiz or MCQs for UPSC Civil Services

The Wet Bulb temperature is the temperature of adiabatic saturation. This is the temperature indicated by a moistened thermometer bulb exposed to the air flow.

Wet Bulb temperature can be measured by using a thermometer with the bulb wrapped in wet muslin. The wet bulb temperature is always lower than the dry bulb temperature but will be identical with 100% relative humidity (the air is at the saturation line).

-The Dry Bulb Temperature refers basically to the ambient air temperature. It is called “Dry Bulb” because the air temperature is indicated by a thermometer not affected by the moisture of the air. Dry-bulb temperature can be measured using a normal thermometer freely exposed to the air but shielded from radiation and moisture.

Statement 1 is correct. Water has a much higher heat capacity than air, meaning the oceans can absorb larger amounts of heat energy with only a slight increase in temperature.

Water’s specific heat capacity is 4200 Jkg-1K-1 and Air’s is 993 Jkg-1K-1 therefore water has 4.23 times more specific heat capacity.

The specific heat capacity is the amount of energy that must be added, in the form of heat, to one unit of mass of the substance in order to cause an increase of one unit in its temperature.

Statement 2 is incorrect. Water is an unusual liquid and has unique properties. Water does indeed expand when warms, and it contracts when it cools, but not at all temperatures. An oddity occurs between 4 and 0 degrees Celsius (about 40- and 32-degrees Fahrenheit).

Between the temperatures of 32 F (0 C) to 40 F (4 C), liquid water actually contracts with increasing temperature.

Explanation: When rubbers bands are twisted and untwisted, it produces a cooling effect. This is called the “elastocaloric” effect, and researchers have suggested that it can be used in a very relevant context today.

 Researchers from multiple universities, including Nankai University in China, have found that the elastocaloric effect, if harnessed, may be able to do away with the need of fluid refrigerants used in fridges and air-conditioners.

 These fluids are susceptible to leakages, and can contribute to global warming. In the elastocaloric effect, the transfer of heat works much the same way as when fluid refrigerants are compressed and expanded.

 When a rubber band is stretched, it absorbs heat from its environment, and when it is released, it gradually cools down.

 In order to figure out how the twisting mechanism might be able to enable a fridge, the researchers compared the cooling power of rubber fibres, nylon and polyethylene fishing lines and nickel-titanium wires.

 They observed high cooling from twist changes in twisted, coiled and super-coiled fibres.

A rainbow is a meteorological phenomenon that is caused by reflection,

refraction and dispersion of light in water droplets resulting in a spectrum of light

appearing as a circular arc in the sky. It is often visible after rainfall due to highly humid

atmosphere and absence of air pollution. The position of the sun and the raindrops in

relation to the observer need to be just right for a rainbow to form:

• The sun needs to be behind the viewer
• The sun needs to be low in the sky, at an angle of less than 42° above the horizon.

The lower the sun in the sky the more of an arc of a rainbow the viewer will see

• Rain, fog or some other source of water droplets must be in front of the viewer

The size of the raindrops does not directly affect the geometry of a rainbow, but mist or fog

tends to disperse the effect more. Rainbows only appear semi-circular over level ground at

sunrise or sunset, when the sun is exactly on the horizon, the majority of the time a smaller

segment of an arc is seen.

Optical fibre is a device which works on the principle of total internal

reflection by which light signals can be transmitted from one place to another with

negligible loss of energy.

Double rainbow.

Statement 1 is correct: Double rainbows are formed when sunlight is reflected twice

within a raindrop with the violet light that reaches the observers eye coming from the

higher raindrops and the red light from lower raindrops.

Statement 2 is correct: A key feature of double rainbows is that the colour sequence in

the second rainbow is reversed, ROYGBIV instead of VIBGYOR order in primary rainbow.

Polarimetry is a sensitive, nondestructive technique for measuring the

optical activity exhibited by inorganic and organic compounds.

• A compound is considered to be optically active if linearly polarized light is rotated

when passing through it.

• A team of astronomers has discovered that the closest known brown dwarf, Luhman

16A, shows signs of cloud bands similar to those seen on Jupiter and Saturn.

• The researchers used an instrument on the Very Large Telescope in Chile to study

polarised light from the Luhman 16 system. Polarisation is a property of light that

represents the direction that the light wave oscillates.

• The polarimetry technique is not limited to brown dwarfs. It can also be applied to

exoplanets orbiting distant stars. The atmospheres of hot, gas giant exoplanets are

similar to those of brown dwarfs

Microbeads are small, solid, manufactured plastic particles that are less than 5mm and don’t degrade or dissolve in water. They may be added to a range of products, including rinse-off cosmetics, personal care and cleaning products.
Microbeads are used as ingredients in these products for a variety of purposes. This includes as an abrasive or exfoliant, a bulking agent, for controlled timed release of active ingredients, and to prolong shelf life. They are also a relatively cheap ingredient.
Microbeads may be found in some products. These include toothpaste, sunscreen, facial scrubs, body wash, cosmetics such as foundation and blush, and other care products.

Both statements are correct.
Ammonium nitrate (NH4NO3) is a crystal-like white solid which is made in large industrial quantities. Its major use is as a source of nitrogen for fertilizer and is also used to create explosives for mining.

Ammonium nitrate does not burn on its own. Instead, it acts as a source of oxygen that can accelerate the combustion (burning) of other materials.
At high enough temperatures ammonium nitrate can violently decompose on its own. This process creates gases including nitrogen oxides and water vapour. It is this rapid release of gases that causes an explosion.

Statement 1 is correct. A desalination plant turns salt water into water that is fit to drink. The most commonly used technology used for the process is reverse osmosis where an external pressure is applied to push solvents from an area of high-solute concentration to an area of low-solute concentration through a membrane.
Statement 2 is incorrect. In India, Tamil Nadu has been the pioneer in using this technology, setting up two up in Chennai. The other states that have proposed these plants are Gujarat, which has announced to set up a 100 MLD RO plant at the Jodiya coast in Jamnagar district.
# Desalination has largely been limited to affluent countries in the Middle East and has recently started making inroads in parts of the United States and Australia

The Nobel Prize in Chemistry 2020 has been awarded jointly to
Emmanuelle Charpentier and Jennifer A. Doudna “for the development of a method for
genome editing.”
Emmanuelle Charpentier and Jennifer A. Doudna have discovered one of gene technology’s
sharpest tools: the CRISPR/Cas9 genetic scissors. Using these, researchers can change
the DNA of animals, plants and microorganisms with extremely high precision.
# The Nobel Prize in Chemistry 2019: John B. Goodenough, M. Stanley Whittingham and
Akira Yoshino “for the development of lithium-ion batteries”.
# The Nobel Prize in Chemistry 2018: Frances H. Arnold “for the directed evolution of
enzymes”, George P. Smith and Sir Gregory P. Winter “for the phage display of peptides and
antibodies”.
# The Nobel Prize in Chemistry 2017: Jacques Dubochet, Joachim Frank and Richard
Henderson “for developing cryo-electron microscopy for the high-resolution structure
determination of biomolecules in solution”.
# The Nobel Prize in Chemistry 2016: Jean-Pierre Sauvage, Sir J. Fraser Stoddart and
Bernard L. Feringa “for the design and synthesis of molecular machines”.

Statement 1 is correct. CRISPR (Clustered Regularly Interspaced Short
Palindromic Repeats) technology is a tool for editing genomes. It allows researchers to
easily alter DNA sequences and modify gene function
CRISPRs are specialized stretches of DNA. The protein Cas9 (CRISPR-associated-9) is an enzyme that acts like a pair of molecular scissors, capable of cutting strands of DNA.
Its many potential applications include correcting genetic defects, treating and preventing the spread of diseases and improving crops.
Statement 2 is correct. CRISPR technology was adapted from the natural defense mechanisms of bacteria and archaea (the domain of single-celled microorganisms).
These organisms use CRISPR-derived RNA and various Cas proteins, including Cas9, to foil attacks by viruses and other foreign bodies. They do so primarily by chopping up and destroying the DNA of a foreign invader. When these components are transferred into other, more complex, organisms, it allows for the manipulation of genes, or “editing.”

Calcium nitrate also known as Norwegian saltpeter is mainly produced as a fertilizer, used for plant nutrition purposes, and for wastewater treatment. It is a source of both calcium and nitrogen, for plants.
‘Calcium Nitrate’ & ‘Boronated Calcium Nitrate’ is now being manufactured for the first time in India by Gujrat State Fertilizers and Chemicals -GSFC India Ltd. GSFC launched these two products in the retail market for the first time from Solan in Himachal Pradesh and Bhavnagar in Gujarat.

Sodium bicarbonate is commonly known as baking soda.

Until six years ago, such materials did not exist but today, researchers believe that they hold the key to‘post-silicon’ electronics.
• VdW materials are made of piles of ultra-thin layers that are held together by weak van der Waals bonds, which arise when atoms are in close proximity.
• The success of graphene — a well-known vdW material — stimulated scientists to look for other 2D crystals, where layers can be changed, added or removed in order to introduce new physical properties such as magnetism.
• Controlling magnetism, as is typical of such materials, could replace the current hard drive assemblies in computers and even become the key to quantum computing.

Scientists around the world have been trying for decades to recreate the unfathomable power of the sun here on Earth, and a team in China has managed to best our local star. Not for very long, though.
• The team operating the Experimental Advanced Superconducting Tokamak (EAST) managed to heat the reactor’s internal plasma to 100 million degrees Celsius (212 million Fahrenheit).
• That’s six times hotter than the sun, but it doesn’t have any net power generation. In stars, hydrogen fuses into helium, and eventually into heavier elements.
• The fusion process releases large amounts of energy, and the byproducts of fusion aren’t radioactive.
• The only nuclear power we’ve managed to utilize on Earth is fission, which requires dangerous radioactive materials and comes with the risk of a reactor meltdown.

India became home to the world’s first-ever thermal battery plant, which was inaugurated in Andhra Pradesh.
Conventional battery technology: is based on the system of charging/discharging cycles that are driven by electricity.
• For example, the Lithium-ion battery, a staple of many electronic devices, consists of electric charges being transferred from electrodes.
• Energy is derived from this battery, when lithium atoms turn into lithium ions (Li+), and get stored when this reaction reverses.
• Therefore, Li-ion batteries work on the basis of electrical energy.

Thermal batteries: on the other hand, use thermal energy to operate, i.e., the energy created by temperature differences.
• Therefore, the energy transfer in thermal batteries helps store heat when heat travels from one part of the battery setup to the other.
• For that to happen, a thermal battery consists of two parts: a cool zone known as sink, and a hot source called source.
• Both these sides consist of compounds known as phase-changing materials (PCMs), which can change their state of matter on the basis of a physical/chemical reaction.

The name Novichok means “newcomer” in Russian, and applies to a group of
advanced nerve agents developed by the Soviet Union in the 1970s and 1980s.
They were known as fourth-generation chemical weapons and were developed under a
Soviet programme codenamed Foliant.
Novichok agents have similar effects to other nerve agents – they act by blocking messages
from the nerves to the muscles, causing a collapse of many bodily functions.
While some Novichok agents are liquids, others are thought to exist in solid form. This
means they could be dispersed as an ultra-fine powder.
Nerve agents enter the body primarily through the respiratory tract, although they may
be absorbed through the eyes or skin. In the liquid state, nerve agents are hazardous via
skin or eye contact and through ingestion. Generally, all nerve agents are highly toxic and
fast acting.
# Britain says Russia used Novichok to poison former spy Sergei Skripal and his daughter
Yulia in the British city of Salisbury two years ago.
# Germany says Novichok was used to poison Alexei Navalny, a critic of Russian President
Vladimir Putin.

Statement 1 is correct. Phosphine is a colorless, flammable, and explosive
gas at ambient temperature.
Statement 2 is incorrect. It is a natural gaseous carrier of phosphorus in its biogeochemical
cycles, has been found ubiquitously present in the environment. Small amounts occur
naturally from the breakdown of organic matter.
# Recent discovery of phosphine on Venus has sparked debate on presence of life outside
Earth.
On rocky planets such as Venus and Earth, phosphine can only be made by life—whether
human or microbe.
Phosphine is manufactured as an agricultural fumigant, is used in the semiconductor
industry, and is a byproduct of meth labs.
But phosphine is also made naturally by some species of anaerobic bacteria—organisms that
live in the oxygen-starved environments of landfills, marshlands, and even animal guts.

Statement 1 is correct. A fuel cell is like a battery in that it generates
electricity from an electrochemical reaction. It uses the chemical energy of hydrogen or
another fuel to cleanly and efficiently produce electricity.
Statement 2 is correct. In hydrogen fuel cell; electricity, water, and heat are the only
products.
# Fuel cell working:
A fuel cell consists of two electrodes—a negative electrode (or anode) and a positive electrode
(or cathode)—sandwiched around an electrolyte.
A fuel, such as hydrogen, is fed to the anode, and air is fed to the cathode. In a hydrogen fuel
cell, a catalyst at the anode separates hydrogen molecules into protons and electrons, which
take different paths to the cathode.
The electrons go through an external circuit, creating a flow of electricity. The protons migrate
through the electrolyte to the cathode, where they unite with oxygen and the electrons to
produce water and heat.
# The Ministry of Road Transport and Highways has notified the Standards for Safety
Evaluation of vehicles being propelled by Hydrogen Fuel Cells.

Fuel cells have strong benefits over conventional combustion-based
technologies currently used in many power plants and cars.
-They produce much smaller quantities of greenhouse gases and none of the air
pollutants that create smog and cause health problems.
– Fuel cells can operate at higher efficiencies than combustion engines, and can convert
the chemical energy in the fuel to electrical energy with efficiencies of up to 60%.
-If pure hydrogen is used as a fuel, fuel cells emit only heat and water as a byproduct.
Hydrogen-powered fuel cells are also far more energy efficient than traditional combustion
technologies.
-Fuel cells are quiet during operation as they have fewer moving parts.

Octane Number/Rating, measure of the ability of a fuel to resist knocking when ignited in a mixture with air in the cylinder of an internal-combustion engine. The octane number is determined by comparing, under standard conditions, the knock intensity of the fuel with that of blends of two reference fuels: iso-octane, which resists knocking, and heptane, which knocks readily.
The higher the number, the better the fuel burns within the engine of a vehicle. Higher performance vehicles require fuels with a higher-octane rating.
Indian Oil has launched world-class premium grade Petrol (Octane 100) branded as XP100 in the country recently.
# Knocking, in an internal-combustion engine, sharp sounds caused by premature combustion of part of the compressed air-fuel mixture in the cylinder.

As with most liquids, water molecules are normally attracted to each other. This attraction creates tension at the surface of the water, often referred to as a thin “skin,” which allows some insects to glide across it.
–When leaves, twigs or other organic substances fall into water and begin decaying, they release compounds known as surfacants.
This interaction breaks the surface tension, which in turn allows air to more easily mix with water and creates bubbles. These bubbles congregate as natural foam.
–Not all foam is natural. Certain man-made products, including detergents can cause foam that is similar in appearance, but may be harmful to fish and other aquatic life.
In addition, human activities that cause an increase in algae or aquatic plant growth such as the introduction of fertilisers can cause plant and algae blooms and an increase in foam production.

Both statements are incorrect.
The HL-2M Tokamak reactor is China’s largest and most advanced nuclear fusion experimental research device.
Located in southwestern Sichuan province and completed late last year, the reactor is often called an “artificial sun” on account of the enormous heat and power it produces.
Fusion is considered the source of energy and is what powers our sun. It merges atomic nuclei to create massive amounts of energy—the opposite of the fission process used in atomic weapons and nuclear power plants, which splits them into fragments.
Unlike fission, fusion does not create radioactive waste, and carries less risk of accidents or the theft of atomic material.
# International Thermonuclear Experimental Reactor (ITER) is an international nuclear fusion research and engineering megaproject, which will be the world’s largest magnetic confinement plasma physics experiment. ITER Members: China, the European Union, India, Japan, Korea, Russia and the United States.

Statement 1 is correct. A tri-hydroid of nitrogen (NH3), ammonia is a building block for ammonium nitrate (NH4NO3) that is used in agriculture as a high-nitrogen fertiliser.
Ammonia is also used as a refrigerant gas, for purification of water supplies, and in the manufacture of plastics, explosives, textiles, pesticides, dyes and other chemicals.
Statement 2 is correct. Ammonia is irritating and corrosive. Exposure to high concentrations of ammonia in air causes immediate burning of the nose, throat and respiratory tract. This can cause bronchiolar and alveolar edema, and airway destruction resulting in respiratory distress or failure.
Inhalation of lower concentrations can cause coughing, and nose and throat irritation. Ammonia’s odor provides adequate early warning of its presence, but ammonia also causes olfactory fatigue or adaptation, reducing awareness of one’s prolonged exposure at low concentrations.

Benzoic acid is an organic compound which is described by the chemical formula C6H5COOH.
• It consists of a carboxyl group attached to a benzene ring. Therefore, benzoic acid is said to be an aromatic carboxylic acid.
• This compound exists as a crystalline, colorless solid under normal conditions.
• It is white and belongs to the family of carboxylic acid.
• The term ‘benzoate’ refers to the esters and salts of C6H5COOH.
• The commercial production of benzoic acid is done via the partial oxidation of toluene with oxygen, catalyzed by manganese or cobalt naphthenates.

Some important uses of C6H5COOH are listed below.
• The production of phenol involves the use of benzoic acid.
• This compound is used in ointments that prevent or treat fungal skin diseases.
• C6H5COOH is used as a preservative in the food industry.
• Benzoic acid is an ingredient in many cosmetic products, such as lipsticks.
• It is also a precursor to benzoyl chloride.
• One of the components of toothpaste, mouthwash, and face-wash creams is C6H5
• This compound is also used in the manufacture of dyes and in insect repellants.

According to the Directorate General Foreign Trade (DGFT) Beach Sand Minerals (BSM) comprised a suite of seven minerals.
• They are limonite, rutile, leucoxene (titanium being mineral), zircon (zirconium being mineral), garnet, sillimanite and monazite (a proscribed substance under the Atomic Energy Act of 1962 since it covers uranium and thorium).
• The suites of BSM were also called atomic minerals. Except garnet and sillimanite, others were prescribed substances under the Atomic Energy Act.

Mankind has known materials such as gold, silver, mercury, iron, phosphorous, sulphur and others since antiquity.
• Alchemists tried making gold out of “base” metals — with no success. But we had to wait until the English school teacher John Dalton who in 1808 came up with his “new system of chemical philosophy”, where he proposed that chemical elements are made of atoms;
• Any given element is made entirely of one kind of atom and that each atom has a characteristic weight; chemical reactions occur when atoms of different elements interact with one another

•Dalton and Thomas Thomson from England and Berzelius from Europe defined the weight of a hydrogen atom as one, and the atomic weights of other elements were measured using this standard.
• By the 1860s, the atomic weights of a large number of elements were published.

The Food Safety and Standards Authority of India (FSSAI) seized one tonne of artificially ripened bananas and plantains from a market in Tiruppur (Tamil Nadu). According to FSSAI officials, a trader had used ripening agent ethephon (2-chloroethylphosphonic acid) on the bananas and plantains kept for sale.

The United Nations announced 2019 as the International Year of the Periodic Table of the Chemical Elements to highlight its first publication in 1869.

 The periodic table as we know it today was first designed by the Russian scientist Dmitri Ivanovich Mendeleev.

 This year marks the 150th anniversary of the first publication of the periodic table by Mendeleev.

 Since its creation, the periodic table has been at the centre of a lot of vivid debates and is now considered as “one of the most important and influential achievements in modern science reflecting the essence not only of chemistry, but also of physics, biology and other disciplines.”

 Mendeleev’s genius lies in the acknowledgement that at the time, not all the elements were known yet, so he left gaps in the table for undiscovered elements

• At that time, only 63 elements had been identified. Still the properties of five other elements (the gaps brilliantly added to complete the table) could already been determined using the table.

Simultaneously removing heavy metals such as arsenic, chromium, cadmium and mercury from waste water with very high efficiency now appears possible, thanks to the work of researchers at the Indian Institute of Technology (IIT) Bombay.

 The carbon-based nanostructure that the team fabricated shows 80-90% adsorption efficiency for all the four heavy metals studied.

 No electricity is required for the nanostructure to remove heavy metals from water as it allows for gravity-driven purification of the water.

 The nanostructures can be recycled and reused multiple times.

 While there is an initial drop of about 8% after the first cycle, the efficiency remains constant at 75-85% in the subsequent cycles.

 The carbon nanostructure is able to adsorb the heavy metals in the wide range of pH conditions — pH 2 to 13.

While conventional sodium sulphur batteries require very high temperature (300 degree C) for operation, researchers at the Indian Institute of technology (IIT) Madras have designed a new sodium sulphur battery that can be operated at room temperature.

By operating the battery at room temperature, the team was able to achieve higher charge storage capacity (technically called the specific capacity) and nearly zero self-discharge when the battery is not being used.

Converting the global-warming compound carbon dioxide into a useful fuel has been engaging the attention of scientists for some time.

 Scientists at the Tata Institute of Fundamental Research (TIFR) have discovered an easier and cheaper way of converting CO2 into methane. Scientists have generally used metal nanoparticles as catalysts for this process.

 But TIFR employed ‘defected silica’ — silicon dioxide with a few oxygen atoms knocked off — instead of the costlier metal nanoparticles.

 ‘Defected silca’ has ‘holes’, where the oxygen atoms used to be. These holes get filled by hydrogen atoms to form silicon hydride. For this, hydrogen molecules, that exist in nature in pairs (hence H2) are ripped apart.

 Each hydrogen atom, then, is desperate to join hands with something; alongside, defected silica is agonising for something to fill the gap where earlier oxygen atoms used to be.

 A happy marriage results. But this marriage is short-lived because carbon dioxide dives in to break the marriage.

 The carbon in CO2 and the hydrogen in silicon hydride desert their spouses and join hands to become methane.

 The leftovers, silicon and oxygen, re-marry to form silicon dioxide — the original catalyst.

Polycrack technology is world’s first patented heterogeneous catalytic

process which converts multiple feed stocks into hydrocarbon liquid fuels, gas, carbon

and water. Polycrack Plant can be fed with all types of Plastic, Petroleum sludge, Unsegregated

MSW (Municipal Solid Waste) with moisture up to 50%, E–Waste, Automobile

fluff, Organic waste including bamboo, garden waste etc., and Jatropha fruit and palm

bunch.

Polycrack has the following advantages over the conventional approach of treating solid

waste:-

• Pre-segregation of waste is not required to reform the waste. Waste as collected can

be directly fed into Polycrack.

• It has high tolerance to moisture hence drying of waste is not required.
• Waste is processed and reformed within 24 hours.
• It is an enclosed unit hence the working environment is dust free.
• Excellent air quality surrounding the plant.
• Biological decomposition is not allowed as the Waste is treated as it is

received.

• The foot print of the plant is small hence the area required for installing the plant is

less when compared with conventional method of processing.

• All constituents are converted into valuable energy thereby making it Zero Discharge

Process.

• Gas generated in the process is re-used to provide energy to the system thereby

making it self-reliant and also bring down the operating cost.

• There is no atmospheric emission during the process unlike other conventional

methods except for combustion gases which have pollutants less than the

prescribed norms the world over.

• Operates around 450 degrees, making it a low temperature process when compared

with other options.

• Safe and efficient system with built-in safety features enables even an unskilled user

to operate the machine with ease.

• Low capital cost and low operating cost.
• Fully automated system requires minimum man power.

NOTE: A patent is defined as a statutory privilege granted by the government to inventors,

and to other persons deriving their rights from the inventor, for fixed years, to exclude other

persons from manufacturing, using or selling a patented product or process.

• Hence a patent can be for a process or for a product. There is strict divergence

between product and process patent regimes. The developed countries follow

product patent system. On the other, process patent system is preferred by the

developing world.

• The two systems are known for their different levels of protection to inventors. Under

a process patent, the patent is granted for a particular manufacturing process, and

not for the product itself.

• Any other person can produce the same product through some other PROCESS,

modifying the various parameters. The implication is that there will be more than

one producer for the same product because of the possibility of different process for

the manufacturing of the product.

A new, curious mineral has been discovered inside a diamond unearthed from a mine in South Africa.

 The mineral has been named goldschmidtite, after Victor Moritz Goldschmidt, the Norwegian scientist acknowledged as the founder of modern geochemistry.

 Goldschmidtite has an unusual chemical signature for a mineral from Earth’s mantle, according to the University of Alberta, a student of which discovered it.

 While the mantle is dominated by elements such as magnesium and iron, goldschmidtite has high concentrations of niobium, potassium and the rare earth elements lanthanum and cerium.

 PhD student Nicole Meyer found a single grain of the mineral in the diamond, unearthed in Koffiefontein, South Africa.

 The university described it as dark green and opaque.

Statement 1 is correct. The leishmaniases are a group of diseases caused by protozoan parasites from more than 20 Leishmania species. These parasites are transmitted to humans by the bite of an infected female phlebotomine sandfly, a tiny – 2–3 mm long – insect vector.
The most common forms are cutaneous leishmaniasis, which causes skin sores, and visceral leishmaniasis, which affects several internal organs (usually spleen, liver, and bone marrow).
Some people have a silent infection, without any symptoms or signs. People who develop clinical evidence of infection usually have fever, weight loss, enlargement (swelling) of the spleen and liver, and abnormal blood tests.
Statement 2 is incorrect. If not treated, severe (advanced) cases of visceral leishmaniasis typically are fatal.
# To recognize the significant contributions towards defining the survival tactics of Leishmania donovani, Society of Biological Chemists (India) has chosen Dr Susanta Kar, Senior Scientist, CSIR-CDRI for this year’s Prof.A N Bhaduri Memorial Lecture Award.

: Statement 1 is correct. Cancer is the name given to a collection of related diseases. In all types of cancer, some of the body’s cells begin to divide without stopping and spread into surrounding tissues.
Cancer cells differ from normal cells in many ways that allow them to grow out of control and become invasive. One important difference is that cancer cells are less specialized than normal cells. That is, whereas normal cells mature into very distinct cell types with specific functions, cancer cells do not. This is one reason that, unlike normal cells, cancer cells continue to divide without stopping.
In addition, cancer cells are able to ignore signals that normally tell cells to stop dividing or that begin a process known as programmed cell death, or apoptosis, which the body uses to get rid of unneeded cells.
Statement 2 is incorrect. National pharmaceutical Pricing Authority (NPPA) regulates the prices of all Drugs as per the Drug Price Control Order (DPCO) 2013.
It fixes the Ceiling Price of scheduled formulations as per the list of medicines specified in the National List of Essential Medicines (NLEM) which are included in the First Schedule of Drug Pricing Control Order (DPCO), 2013.
First Schedule of DPCO, 2013 also includes select drugs used for the treatment of cancer. However, there has been a long standing felt need to further regulate the Non Scheduled segment also where high markups have led to arbitrary pricing practices.

Aptameters are oligonucleotide or peptide molecules that bind to a specific target molecule. Aptamers can be classified as: DNA or RNA aptamers consisting of (usually short) strands of oligonucleotides and Peptide aptamers consisting of one (or more) short variable peptide domains, attached at both ends to a protein scaffold.
These the artificial single-stranded DNA or RNA sequences (or peptides) fold into secondary and tertiary structures making them bind to certain targets with extremely high specificity.
# Birla Institute of Technology, Ranchi, has initiated the research with support from the Science and Engineering Research Board (SERB) under DST on the covid-19 detection kit, which can be stored under less stringent conditions.
Scientists are working on detecting a target spike protein using bioinformatics tools. The kit will use aptamer (a biosensor) to detect SARS-Co-V2.

Contaminated water and poor sanitation are linked to transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid, and polio.
Diarrhoea is the most widely known disease linked to contaminated food and water but there are other hazards. In 2017, over 220 million people required preventative treatment for schistosomiasis – an acute and chronic disease caused by parasitic worms contracted through exposure to infested water.
In 2017, 71% of the global population (5.3 billion people) used a safely managed drinking-water service – that is, one located on premises, available when needed, and free from contamination.
In 2010, the UN General Assembly explicitly recognized the human right to water and sanitation.
# Data Source: World Health Organisation Website.

Statement 1 is correct. Glanders is an infectious disease that is caused by the bacterium Burkholderia mallei.
Statement 2 is incorrect. Though not common, people have gotten glanders from sick animals. People who are in close contact with animals that have glanders are more likely to get the disease than those who are not.
# In the past, the germs that cause glanders, the bacteria called Burkholderia mallei, have been used as a biological weapon during wars.

Option 1 and 2 are correct. Passive immunity is the transfer of antibody produced by one human or another animal to another. Passive immunity provides protection against some infections, but this protection is temporary.
-The most common form of passive immunity is that which an infant receives from its mother. Antibodies are transported across the placenta during pregnancy. As a result, a full-term infant will have the same antibodies as its mother. These antibodies will protect the infant from certain diseases for up to a year.
-Many types of blood products contain antibody. Some products (e.g., washed or reconstituted red blood cells) contain a relatively small amount of antibody and some (e.g., intravenous immune globulin and plasma products) contain a large amount which is used for antibody transfusion.

Option 3 is incorrect. Active immunity is stimulation of the immune system to produce antigen-specific humoral (antibody) and cellular immunity. Unlike passive immunity, which is temporary, active immunity usually lasts for many years, often for a lifetime.
-One way to acquire active immunity is to survive infection with the disease-causing form of the organism.
-Another way to produce active immunity is by vaccination. Vaccines interact with the immune system and often produce an immune response similar to that produced by the natural infection, but they do not subject the recipient to the disease and its potential complications.

All of the above statements are correct.
The immune system uses several tools to fight infection. Blood contains red blood cells, for carrying oxygen to tissues and organs, and white or immune cells, for fighting infection. These white cells consist primarily of macrophages, B-lymphocytes and T-lymphocytes:
Macrophages are white blood cells that swallow up and digest germs, plus dead or dying cells. The macrophages leave behind parts of the invading germs called antigens. The body identifies antigens as dangerous and stimulates antibodies to attack them.
B-lymphocytes are defensive white blood cells. They produce antibodies that attack the antigens left behind by the macrophages. Each B cell produces a single species of antibody, each with a unique antigen-binding site.
T-lymphocytes are another type of defensive white blood cell. There are two major types of T cells: the helper T cell and the cytotoxic T cell. As the names suggest helper T cells ‘help’ other cells of the immune system, whilst cytotoxic T cells kill virally infected cells and tumors.

Both statements are correct.
There are four types of influenza viruses: A, B, C and D. Human influenza A and B viruses cause seasonal epidemics of disease (known as the flu season) almost every year.

Influenza A viruses also are found in many different animals, including ducks, chickens, pigs, whales, horses and seals.
Influenza A viruses are divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N).

Influenza type C infections generally cause mild illness and are not thought to cause human flu epidemics. Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people.

: Statement 1 is incorrect. The SARS-CoV-2 is a positive-sense single-stranded RNA virus.
An RNA virus is a virus that has RNA (ribonucleic acid) as its genetic material. RNA viruses replicate their genomes using virally encoded RNA-dependent RNA polymerase (RdRp).The RNA may be either double- or single-stranded.

Statement 2 is correct. The SARS-COV-2 has spike proteins which binds with the Angiotensin-converting enzyme 2 (ACE2) on cell membranes in human body.

Both statements are correct.
Thalassemia is an inherited blood disorder caused when the body doesn’t make enough of a protein called hemoglobin, an important part of red blood cells.
When there isn’t enough hemoglobin, the body’s red blood cells don’t function properly and they last shorter periods of time, so there are fewer healthy red blood cells traveling in the bloodstream.
People with thalassemia may have mild or severe anemia because Red blood cells carry oxygen to all the cells of the body and when there are not enough healthy red blood cells, there is also not enough oxygen delivered to all the other cells of the body..

Statement 1 is correct. Adenoviruses are common viruses that cause a range of illness. They can cause cold-like symptoms, fever, sore throat, bronchitis, pneumonia, diarrhea, and pink eye (conjunctivitis).

Adenoviruses usually spread from infected people to others through: close personal contact such as touching or shaking hands, the air by coughing and sneezing, touching objects or surfaces with adenoviruses on them then touching your mouth, nose, or eyes.

Statement 2 is correct. Vectors are viruses that have had the gene responsible for replication removed. Therefore, they no longer pose any threat of infection. Adenoviral vectors are considered safe, and are some of the easiest to engineer.

Scientists use vectors to transport genetic material from a different virus -the one that is being vaccinated against -into a human cell.

Sputnik V uses two types of adenoviral vectors — Ad5 and Ad26 — in the COVID-19 vaccine. In this way, they trick the body, which has developed immunity against the first type of vector and boost the effectiveness of the vaccine with the second shot using a different vector.

Oxford University and China’s Cansino Biologics are also using Adenovirus vector for developing COVID-19 vaccine.

The case-fatality rate is the proportion of persons with a particular condition (cases) who die from that condition.

The overall case-fatality rate of Middle East respiratory syndrome coronavirus (MERS-CoV) infection is around 35%.

Ebola virus disease (EVD), formerly known as Ebola haemorrhagic fever, is a rare but severe, often fatal illness in humans. The average EVD case fatality rate is around 50%. Case fatality rates have varied from 25% to 90% in past outbreaks.

The case-fatality ratio of SARS is estimated to range from 0% to more than 50% depending on the age group affected, with an overall CFR estimate of approximately 15%. A global case-fatality ratio of 11% was recorded at the end of the outbreak (2003).

COVID-19 fatality rate has been hovering significantly below 5% globally. India’s CFR has been reported to be around 2%.

Both statements are correct.

Sickle Cell Disease is a group of inherited red blood cell disorders.

Healthy red blood cells are round, and they move through small blood vessels to carry oxygen to all parts of the body. In someone who has SCD, the red blood cells become hard and sticky and look like a C-shaped farm tool called a “sickle”.

The sickle cells die early, which causes a constant shortage of red blood cells. Also, when they travel through small blood vessels, they get stuck and clog the blood flow. This can cause pain and other serious problems such infection, acute chest syndrome and stroke.

Option 1 is correct. Thalassemia is an inherited (passed from parents to

children through genes) blood disorder caused when the body doesn’t make enough of a

protein called hemoglobin, an important part of red blood cells.

When there isn’t enough hemoglobin, the body’s red blood cells don’t function properly and

they last shorter periods of time, so there are fewer healthy red blood cells traveling in the

bloodstream.

Option 2 is correct. Sickle Cell Disease is a group of inherited red blood cell disorders.

Healthy red blood cells are round, and they move through small blood vessels to carry

oxygen to all parts of the body. In someone who has SCD, the red blood cells become hard

and sticky and look like a C-shaped farm tool called a “sickle”.

The sickle cells die early, which causes a constant shortage of red blood cells. Also, when

they travel through small blood vessels, they get stuck and clog the blood flow. This can

cause pain and other serious problems such infection, acute chest syndrome and stroke.

# Second phase of “Thalassemia Bal Sewa Yojna” for the underprivileged Thalassemic

patients was launched recently. It is a Coal India CSR funded Hematopoietic Stem Cell

Transplantation (HSCT) program that aims to provide a one-time cure opportunity for

Haemoglobinopathies like Thalassaemia and Sickle Cell Disease for patients who have a

matched family donor.

Statement 1 is correct. Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tickborne virus (genus Phlebovirus, family Phenuiviridae) that can cause a mild to severe febrile illness similar to hemorrhagic fever.

SFTS is characterized by acute high fever, thrombocytopenia, leukopenia, elevated serum hepatic enzymes, gastrointestinal symptoms, and multiorgan failure.

Statement 2 is incorrect. Severe fever with thrombocytopenia syndrome (SFTS) illness was first confirmed in China in 2009. It was retrospectively identified in South Korea in 2010 and the western regions of Japan in 2013.

Recently the disease has killed seven and infected at least 60 in China.

Both statements are correct.

Angiotensin-converting enzyme 2 (ACE2) ACE2 is a protein on the surface of many cell types. It is an enzyme that generates small proteins – by cutting up the larger protein angiotensinogen.

ACE2 is present in many cell types and tissues including the lungs, heart, blood vessels, kidneys, liver and gastrointestinal tract. It is present in epithelial cells, which line certain tissues and create protective barriers.

The SARS-CoV-2 virus binds to ACE2, using the spike-like protein on its surface, prior to entry and infection of cells. Hence, ACE2 acts as a cellular receptor for the virus that causes COVID-19.

Statement 1 is correct. Convalescent plasma, extracted from the blood of

patients recovering from an infection, is a source of antibodies against the infection. The

therapy involves using their plasma to help others recover.

Statement 2 is correct. Blood is a specialized body fluid. It has four main components:

plasma, red blood cells, white blood cells, and platelets.

Plasma is the largest part of your blood. It, makes up more than half (about 55%) of its

overall content. When separated from the rest of the blood, plasma is a light-yellow liquid.

Plasma carries water, salts and enzymes.

The main role of plasma is to take nutrients, hormones, and proteins to the parts of the

body that need it. Cells also put their waste products into the plasma. The plasma then

helps remove this waste from the body. Blood plasma also carries all parts of the blood

through your circulatory system.

Statement 1 is correct. Hepatitis C is a liver disease caused by the hepatitis

C virus (HCV): the virus can cause both acute and chronic hepatitis, ranging in severity

from a mild illness lasting a few weeks to a serious, lifelong illness. Hepatitis C is a major

cause of liver cancer.

Statement 2 is correct. The hepatitis C virus is a bloodborne virus: the most common

modes of infection are through exposure to small quantities of blood. This may happen

through injection drug use, unsafe injection practices, unsafe health care, transfusion of

unscreened blood and blood products, and sexual practices that lead to exposure to blood.

# This year’s Nobel Prize winners in Medicine; Harvey J. Alter, Michael Houghton and Charles

1. Rice made seminal discoveries that led to the identification of a novel virus, Hepatitis C

virus.

The National Viral Hepatitis Control Program was launched by Ministry of

Health and Family Welfare on the World Hepatitis Day, 28th July 2018.

It is an integrated initiative for the prevention and control of viral hepatitis in India to achieve Sustainable Development Goal (SDG) 3.3 which aims to ending viral hepatitis by 2030.

Statement 1 is correct.

Aim of the program:

– Combat hepatitis and achieve country wide elimination of Hepatitis C by 2030;

– Achieve significant reduction in the infected population, morbidity and mortality associated with Hepatitis B and C viz. Cirrhosis and Hepato-cellular carcinoma (liver cancer);

– Reduce the risk, morbidity and mortality due to Hepatitis A and E.

Statement 2 is correct. Components of NVHCP: Prevention, Diagnosis and Treatment,

Monitoring and Evaluation, Surveillance and Research; and Training and Capacity

Building

Hepatitis A is usually a short-term infection. Hepatitis B and hepatitis C can also begin as

short-term infections, but in some people, the virus remains in the body and causes chronic

(long-term) infection. There are vaccines to prevent hepatitis A and hepatitis B; however,

there is no vaccine for hepatitis C.

Hepatitis means inflammation of the liver. When the liver is inflamed or damaged, its function can be affected. The common hepatitis viruses are hepatitis A virus, hepatitis B virus, and hepatitis C virus.

Hepatitis A, hepatitis B, and hepatitis C are liver infections caused by three different viruses. Although each can cause similar symptoms, they are spread in different ways and can affect the liver differently

The presence of the Cat Que virus has been largely reported in Culex

mosquitoes in China and in pigs in Vietnam.

The domestic pigs are considered to be the primary mammalian hosts for CQV.

CQV belongs to the Simbu serogroup and infects both humans and economically important

livestock species. Humans can get infected through mosquitoes as well.

# In a study published in July in the Indian Journal of Medical Research, scientists from the

Pune-based Maximum Containment Laboratory and ICMR-National Institute of Virology have

noted the presence of antibodies against the Cat Que virus (CQV) in two human serum

samples.

A disease is said to be in Community transmission stage when there is no clear source of origin of the infection in a new person/community. It can no longer be identified who became infected after being exposed to someone, who interacted with infected people.

The source and chain of infections can no longer be established. Therefore, contact tracing becomes difficult and has limited use in arresting the spread of disease.

# Herd immunity occurs when a large portion of a community becomes immune to a disease, making the spread of disease from person to person unlikely. This can happen in two ways:

1. Many people contract the disease and in time build up an immune response to it (natural immunity)
2. Many people are vaccinated against the disease to achieve immunity.

Immunogenicity is the ability of a foreign substance, such as an antigen, to provoke an immune response in the body of a human or other animal. It is the ability to induce a humoral and/or cell-mediated immune responses.

Antigenicity is the ability to be specifically recognized by the antibodies generated as a result of the immune response to the given substance.

Statement 1 is correct. Trans fats are a byproduct of a process called hydrogenation that is used to turn healthy oils into solids and to prevent them from becoming rancid.

Statement 2 is incorrect. Trans fats raise the bad (LDL) cholesterol levels and lower good (high-density lipoprotein) HDL cholesterol levels. Eating trans fats increases risk of developing heart disease and stroke. It’s also associated with a higher risk of developing type 2 diabetes.

# World Food Day is observed on Oct. 16 and this year’s theme is Grow, Nourish, sustain.

Vitamin A is involved in immune function, vision, reproduction, and cellular communication. Two forms of vitamin A are available in the human diet: preformed vitamin

A (retinol and its esterified form, retinyl ester) and provitamin A carotenoids.

Concentrations of preformed vitamin A are in liver and fish oils, milk and eggs, which also include some provitamin A. Most dietary provitamin A comes from leafy green vegetables, orange and yellow vegetables, tomato products, fruits, and some vegetable oils.

# Three out of four rural Indians cannot afford a nutritious diet, according to a paper recently published in journal Food Policy.

The highly infectious variant of SARS-COV-2 that has been reported to have emerged in south-east England that is spreading rapidly to the rest of the UK and is already present elsewhere in the world.

The World Health Organisation said its Evolution Working Group is working closely with the UK medical authorities to understand how the variant, now called B.1.1.7, is likely to affect the course of the pandemic. It has been detected in the Netherlands, Denmark and Australia.

Scientists say two aspects of B.1.1.7 give cause for concern. One is the unprecedented number of mutations it carries. The other is the speed with which it is supplanting other strains of the Sars-Cov-2 virus in south-east England.

A mutation is a change in a DNA sequence. Mutations can lead to changes in the structure of an encoded protein or to a decrease or complete loss in its expression.

–When a cell divides, it makes a copy of its DNA — and sometimes the copy is not quite perfect. That small difference from the original DNA sequence is a mutation.

— Mutations can also be caused by exposure to specific chemicals or radiation. Ultraviolet (UV) light has strong genotoxic effects to produce DNA damage, induce mutations, and, in the worst case, cause the development of tumors.

Both statements are correct.

The FNCAS9 Editor-Limited Uniform Detection Assay (FELUDA) test is a paper strip test for diaagnosis of SARS-COV-2.

It uses CRISPR-Cas technology for the detection of genes specific to SARS-CoV-2 virus.

In this method, a protein called FnCas9 and a guide RNA (gRNA) which helps in recognising the viral genes is used. If the patient sample has the viral gene, this gRNA-FnCas9 complex binds to the gene and using a paper strip this binding can be visualised.

Statement 1 is correct. Members of the coronavirus family have sharp bumps that protrude from the surface of their outer envelopes. Those bumps are known as spike proteins. They’re actually glycoproteins. That means they contain a carbohydrate (such as a sugar molecule).

Statement 2 is correct. Spike proteins play an important role in how these viruses infect their hosts. S proteins can change shape to interact with a protein on the surface of human cells. Those spike proteins latch the virus onto a cell. This allows them to get entry into those cells.

Without the S protein, viruses like the novel SARS-CoV-2 would not be able to interact with the cells of potential hosts like animals and humans to cause infection. As a result, the S protein represents an ideal target for vaccine and antiviral research endeavors.

A new variant of SARS- CoV 2 virus [Variant Under Investigation (VUI)-20212/01] also referred to as B.1.1.7 has been reported by the Government of United Kingdom (UK) to World Health Organization (WHO).

This variant is estimated by European Center for Disease Control (ECDC) to be more transmissible and affecting younger population. This variant is defined by a set of 17 changes or mutations. One of the most significant is an N501Y mutation in the spike protein that the virus uses to bind to the human ACE2 receptor. Changes in this part of the spike protein may result in the virus becoming more infectious and spreading more easily between people.

The new variant known as 501Y.V2 was discovered through routine surveillance by a network of laboratories in South Africa.

South Africa reported last week that scientists have found a new genetic mutation which might be responsible for the recent surge in Covid-19 cases in South Africa.

The new variant has multiple changes in the spike protein, the part of the virus that binds to cells inside the human body and that is also the main target for many of the antibodies produced during infection or after vaccination. Scientists have isolated one particular mutation – N501Y, common to both the new UK variant and that from South Africa – which they believe is important to its ability to spread fast.

Statement 1 is correct. Shigella bacteria cause an infection called shigellosis. Most people with Shigella infection have diarrhea (sometimes bloody), fever, and stomach cramps. Symptoms usually begin 1–2 days after infection and last 7 days.

Shigella is very contagious. People get infected with shigella when they come in contact with and swallow small amounts of bacteria from the stool of a person who is infected with shigella.

Statement 2 is correct. Children under age 10 are most likely to get shigella infection but it can occur at any age.

# Recently, several cases of the Shigella infection have been reported in North Kerala.

Keratinocytes are the primary type of cell found in the epidermis, the outermost layer of the skin.

 In humans they constitute 90% of epidermal skin cells.

 Basal cells in the basal layer (stratum basale) of the skin are sometimes referred to as basal keratinocytes.

 By using an indigenously developed hydrogel made of a polymer (polyacrylamide) in lieu of the conventional plastic tissue culture plates, researchers at the Indian Institute of Technology (IIT) Bombay have been able to achieve many-fold increase in the number of skin cells (keratinocytes) cultured in the lab.

• Unlike traditional methods, no feeder layer or drug is needed when cells are grown on the hydrogel substrate.

The “G Finder survey” is often seen in news is related

It is encouraging that India was reported to be the fourth largest funder of research and development (R&D) in neglected diseases as per the G Finder Survey which tracks global investments in R&D for the neglected diseases.

 This reflects the government’s commitment towards addressing the innovation problem in neglected diseases.

 Neglected diseases are mostly tropical infectious diseases, and the market size for drugs for such diseases is small due to their limited geographical incidence.

 To highlight the common problem of lack of innovation for drugs, diagnostics and vaccines for this basket of diseases, WHO started addressing these as neglected diseases from late 1980s.

 Some examples of neglected diseases are malaria, tuberculosis, leishmaniasis (kala azar), dengue, leprosy, lymphatic filariasis and diarrhoeal diseases.

NOTE: These diseases face an innovation deficit as they are neglected in R&D efforts of the pharmaceutical industry.

 However, it is not just the neglected diseases in the developing world that face this innovation deficit.

 Several rare diseases that affect the developed markets are called “orphan diseases.”

 These are called orphans because the pharmaceutical industry does not find it profitable to develop and market products intended for only a small number of patients suffering from rare diseases.

Acute encephalitis syndrome (AES) is a serious public health problem in India. It is characterized as acute-onset of fever and a change in mental status (mental confusion, disorientation, delirium, or coma) and/or new-onset of seizures in a person of any age at any time of the year.

 The syndrome most commonly affects children and young adults and can lead to considerable morbidity and mortality.

 Viruses are the main causative agents in AES cases, although other sources such as bacteria, fungus, parasites, spirochetes, chemicals, toxins and noninfectious agents have also been reported over the past few decades.

 In May-June 2019, the acute encephalitis syndrome (AES) in Bihar’s Muzaffarpur, Vaishali, Sheohar and East Champaran districts has so far claimed the lives of over 100 children.

 More than 400 children with AES have been admitted to various hospitals. Most of the deaths have been attributed to low blood sugar level (hypoglycaemia).

 In Bihar, convulsions in children (which is AES) are found in combination with hypoglycaemia.

Japanese Encephalitis (JE) is a mosquito-borne viral infection of the brain. There is, however, a debate about the origin of the disease and whether it is enteroviruses — caused by virus found in pigs and birds. There is no cure for JE.

 The efficacy of the JE vaccine is between 85-90%. The lessons learnt from polio vaccination drives is that people left out of each round of vaccination are the most disenfranchised, most likely to take ill and least likely to seek medical care in time.

 One hundred and ninety positive cases of Japanese Encephalitis (JE) have been reported and 49 people have died of the vector-borne disease in Assam since January 2019 to June 2019.

 Assam is an ecologically favorable region for the spread of JE due to heavy rainfall, large paddy fields and water bodies and pig farming almost throughout the State.

 Pigs act as amplifying host for the JE virus transmitted through culex mosquito, as do wading birds such as herons and egrets.

A virus named after Kampung Sungai Nipah, a village in Malaysia, where it was first discovered in 1998-99.

 According to the World Health Organization (WHO) Nipah is Zoonotic Virus. “A zoonosis is any disease transmitted from vertebrate animals to humans.”

 It could be caused by a virus, bacteria, fungi or parasite; some examples include anthrax, bird flu, ebola, dengue, rabies, malaria, swine flu and leptospirosis.

 Nipah is believed to be transmitted from what are called flying foxes, or mega bats, so called because they are the largest bat species. They eat fruits and live in trees.

 These are a part of the old-world fruit bat family, called pteropid bats. Bats often end up being reservoirs for a number of severe infectious diseases, including Ebola, SARS coronavirus, Nipah and Hendra.

 Nipah is an RNA or Ribonucleic Acid virus. “RNA viruses are the most common cause of emerging diseases in humans, attributable to the high mutation rate in RNA viruses compared to DNA viruses,” says the book Essential Human Virology.

 Nipah belongs to a genus (category, in layperson speak) called the Henipavirus; the Hendra virus, also found on pteropid bats, belongs to this category too.

 The virus, which is classified as Bio-safety Level 4, meaning that it is highly infectious and needs a maximum containment facility, can be confirmed by an ELISA, RT-PCR or Serum Neutralization Test.

 The incubation period is anywhere between 5-14 days, but it can soon affect the respiratory and nervous system and patients can go into delirium or coma. Unfortunately, there is no definite treatment, except intensive supported care.

On September 3 (2019), Bangladesh, Bhutan, Nepal and Thailand became the first four countries in the World Health Organization’s south-east Asia region to have successfully controlled hepatitis B. The virus is said to be controlled when the disease prevalence is reduced to less than 1% among children less than five years of age.

Bats serves as natural hosts for numerous viruses including Ebola virus, Nipah virus, corona viruses such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) and the 2019 novel corona virus that has infected nearly 10,000 people and killed over 200 others.

 Even as these viruses cause harm in humans, they rarely if at all cause any harmful effects in bats. This is the case even when the viral load is extremely high in bats.

 The reason why bats can harbour these viruses without getting affected is simply because bats can avoid excessive virus-induced inflammation, which often causes severe diseases in animals and people infected with viruses.

 The researchers found that significantly reduced inflammation in bats was because activation of an important protein — NLRP3 — that recognises both cellular stress and viral/bacterial infections was significantly dampened in bat immune cells.

 Studying further, the researchers found that reduced activation of the NLRP3 protein was in turn due to impaired production of mRNA (transcript).

 Since mRNA production is impaired the NLRP3 protein production gets compromised leading to less amount of the protein being produced.

 But this was not the case with mice and humans — there was no impairment to mRNA production so the NLRP3 protein was unaffected

The traces pesticides leave in treated products or those left by veterinary drugs in animals are called “residues”.

 The traces pesticides leave in treated products or those left by veterinary drugs in animals are called “residues”.

 A study of fruits and vegetables grown in the Nilgiris has found that some of the produce might be harbouring high levels of pesticide, beyond what is considered advisable. This was mainly true of potato and carrot.

 While the Food Safety and Standards Authority of India (FSSAI) prescribes a maximum residual level (MRL) for some of the organophosphate pesticides used, it does not prescribe it for some other pesticides used in the cultivation of fruit and vegetables.

In a Rapid Communication published on January 14 – 2020, the World Health Organization (WHO) had mentioned that the India-made Truenat MTB, a molecular diagnostic test to diagnose pulmonary and extrapulmonary TB and rifampicin-resistant TB, has high diagnostic accuracy.

 Truenat MTB has “high diagnostic accuracy as initial test to diagnose TB and to sequentially detect rifampicin resistance”, says the WHO Communication.

 Truenat MTB will be used as an initial test to diagnose TB thus replacing sputum smear microscopy.

 Truenat is developed by the Goa-based Molbio Diagnostics.

 The company was provided with technical assistance and resources by the Foundation for Innovative New Diagnostics (FIND) to help commercialize Truenat. Indian Council of Medical Research (ICMR) had assessed and validated the diagnostic tool.

Neglected tropical diseases (NTDs) – a diverse group of communicable diseases that prevail in tropical and subtropical conditions in 149 countries – affect more than one billion people and cost developing economies billions of dollars every year.

Populations living in poverty, without adequate sanitation and in close contact with infectious vectors and domestic animals and livestock are those worst affected.

As of 2017, the World Health Organization categorizes the following communicable diseases as neglected tropical diseases (NTDs):

 Buruli Ulcer

 Chagas Disease

 Chromoblastomycosisexternal icon

 Cysticercosis

 Dengue Fever

 Dracunculiasis (Guinea Worm Disease)

 Echinococcosis

 Fascioliasis

 Human African Trypanosomiasis (African Sleeping Sickness)

 Leishmaniasis

 Leprosy (Hansen’s Disease)

 Lymphatic Filariasis

 Mycetoma

 Onchocerciasis

 Rabies

 Schistosomiasis

 Soil-transmitted Helminths (STH) (Ascaris, Hookworm, and Whipworm)

 Trachoma

 Yawsexternal icon

Many plant-based products, especially legumes such as chickpeas, beans, soybeans, contain FODMAP compounds that are poorly digestible and cause unpleasant intestinal symptoms, but now researchers have succeeded in breaking down FODMAPs with enzymes and producing new, stomach-friendly plant-based food products.

 FODMAPs are short-chain carbohydrate molecules that are poorly absorbed in the human small intestine.

 These non-absorbed compounds move along to the large intestine, where intestinal microbes feed on them.

 This results in the production of gases that causes symptoms especially for those suffering from intestinal disorders.

 The research team focused on two key FODMAP compounds: galactan and fructan.

 Galactan is abundant in, for example, legumes, while fructan is found in many cereals, among other things.

A traditional drug developed by the Defence Research and Development Organisation (DRDO) for treating vitiligo or leucoderma is now available for commercial sale in India.

 The herbal drug, called Lukoskin, was developed by scientists of the Defence Bio-Energy Research (DIBER) centre at Haldwani in Uttarakhand.

 Developer conferred ‘Science Award’ for ‘Lukoskin’ that treats the skin condition.

 Ahead of the International Vitiligo Day, an herbal drug developed by the Defence Research and Development Organisation (DRDO) offers a new hope to those suffering from leucoderma, a condition in which white patches develop on the skin.

Botulinum is a natural toxin produced by a bacterium known as Clostridium

botulin. It produces the toxin when it starts reproducing.

• The bacterium is commonly found in the soil, river, and sea water.
• There are around eight types — A, B, C1, C2, D, E, F, and G — of botulinum toxin

and they are distinguishable when diagnosed. But all types of toxins attack the

neurons, which leads to muscle paralysis.

• Botulinum affects both humans and animals but the type of the toxin varies —

botulinum C in birds and A, B and E in humans. The toxin has been recognised as

a major cause of mortality in wild birds since the 1900s.

• Avian botulism killed over 18,000 birds in and around Rajasthan’s Sambhar

Lake.

Measles.

• Measles is caused by a virus in the paramyxovirus family and it is normally

passed through direct contact and through the air.

• The virus infects the respiratory tract, and then spreads throughout the body.

Measles is a human disease and is not known to occur in animals.

• Measles is a highly contagious, serious disease caused by a virus. Before the

introduction of measles vaccine in 1963 and widespread vaccination, major

epidemics occurred approximately every 2–3 years and measles caused an estimated

2.6 million deaths each year.

• Accelerated immunization activities have had a major impact on reducing measles

deaths. During 2000– 2018, measles vaccination prevented an estimated 23.2

million deaths. Global measles deaths have decreased by 73% from an estimated

536000 in 2000 to 142,000 in 2018.

A nucleotide is an organic molecule that is the building block of DNA and

RNA.

• They also have functions related to cell signaling, metabolism, and enzyme

reactions.

• A nucleotide is made up of three parts: a phosphate group, a 5-carbon sugar,

and a nitrogenous base.

• The four nitrogenous bases in DNA are adenine, cytosine, guanine,

and thymine.

• RNA contains uracil, instead of thymine.
• A nucleotide within a chain makes up the genetic material of all known living things.
• They also serve a number of functions outside of genetic information storage, as

messengers and energy moving molecules.

Archaea.

• Archaea (singular archaeon) are a primitive group of microorganisms that thrive

in extreme habitats such as hot springs, cold deserts and hyper-saline lakes.

• These slow-growing organisms are also present in the human gut, and have a

potential relationship with human health.

• They are known for producing antimicrobial molecules, and for anti-oxidant activity

with applications in eco-friendly waste-water treatment

A pack animal is a type of animal used by humans to carry heavy loads. These animals carry goods and supplies upon their backs across long distances or difficult terrain.

 They are not to be confused with draft animals, which pull weight on a cart or sled. The use of animals to carry cargo dates as far back as 3500 BC.

 Historical evidence suggests that donkeys have served as pack animals for longer than any other species. Other types of common pack animals include camels, yaks, horses, llamas, oxen, and water buffalos.

 Horses are used as a draught animal even in the Western countries.

 Dogs and reindeer are used in North America, North Europe and Siberia to draw sledges over snow-covered ground.

 Mules are preferred in the mountainous regions; while camels are used for caravan movement in deserts. In India, bullocks are used for pulling carts.

An assessment of antibiotic pollution in rivers across the world shows that the concentration of antibiotics in some rivers is much higher than what is considered safe.

 According to the antimicrobial resistance (AMR) industry alliance standards, the safe level ranges from 20-32,000 nanogramme per litre, depending on the antibiotic.

 However, in Bangladesh, the antibiotic metronidazole was found to 300 times the safe level — this was 170 times higher than what was estimated in London’s River Thames.

 The researchers — who presented their findings at the two day annual meeting of the Society of Environmental Toxicology and Chemistry (SETAC) in Helsinki, which began on May 27 — estimated presence of 14 antibiotics in rivers of 72 countries across six continents.

 A total of 711 sites were tested and antibiotics were found at 65 per cent of them.

 Trimethoprim, an antibiotic used to treat urinary tract infection, was found at 307 of the 711 sites tested.

 Ciproflaxacin most frequently exceeded safe levels, surpassing the safety threshold at 51 places.

Statement 1 is correct. The immune system develops a defense against

antigens, which are substances that can stimulate the immune system. This defense is

known as the immune response and usually involves the production of:

–Protein molecules (immunoglobulins or antibodies, the major component of humoral

immunity) by B-lymphocytes (B-cells)

-Specific cells, including T-lymphocytes (also known as cell-mediated immunity).

Statement 2 is correct. There are five immunoglobulin classes (isotypes) of antibody

molecules: IgG, IgM, IgA, IgE, and IgD.

–Immunoglobulin A (IgA), which is found in high concentrations in the mucous

membranes, particularly those lining the respiratory passages and gastrointestinal tract, as

well as in saliva and tears.

–Immunoglobulin G (IgG), the most abundant type of antibody, is found in all body fluids