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Thrombin is a naturally occurring enzyme that converts fibrinogen into fibrin.

Key Points

• Blood clotting or coagulation is a mechanism that prevents the loss of blood during injury.
• During injury, the damaged platelets release the enzyme, thrombokinase that converts the inactive prothrombin into active thrombin.
• The thrombin formed converts the soluble fibrinogen into insoluble fibrin.
• Conversion of fibrinogen into fibrin is an integral step in clot formation.
• Calcium ions are essential during blood clotting.

Hence Ca2+ is essential for both activation and action of thrombin.

Additional Information

• Sodium: The human body requires a small amount of sodium to conduct nerve impulses, contract and relax muscles, and maintain the proper balance of water and minerals. It is estimated that we need about 500 mg of sodium daily for these vital functions.
• Chloride is, after sodium, the most abundant electrolyte in serum, with a key role in the regulation of body fluids, electrolyte balance, the preservation of electrical neutrality, and acid-base status and it is an essential component for the assessment of many pathological conditions.
• Magnesium is an important mineral, playing a role in over 300 enzyme reactions in the human body. Its many functions include helping with muscle and nerve function, regulating blood pressure, and supporting the immune system.

A mixed heart means the heart in which the oxygenated and the deoxygenated blood are mixed.

Key Points

• Amphibians and most reptiles have a heart with three chambers—two atria and a single ventricle.
• These animals also have separate circuits of blood vessels for oxygenating blood and delivering it to the body.
• Deoxygenated blood returning from the body empties into the right atrium.

Important Points

• All reptiles, with the exception of crocodiles, have a three-chambered heart – two auricles and one ventricle.
• This type is more advanced than that of fish but not as advanced as that possessed by mammals.
• However, the ventricle has an incomplete partition that divides it into 2 sub-chambers.
• The right sub-chamber is called the right ventricle or calum pulmonale while the left subchamber is called the left ventricle or calum venosum.
• There is also a third subchamber called cavum arteriosum towards the top of the ventricle.
• It is connected by a valve to the left ventricle.
• Deoxygenated blood enters the right atrium and moves into the right sub-chamber of the ventricle.
• Due to incomplete separation though, it also leaks into and fills the left ventricle. The blood then moves up from the ventricle into the lungs for oxygenation. This comes back down and fills the third chamber – cavum arteriosum – temporarily shutting it off.  The blood then moves into the left ventricle and from there the rest of the body.

Hence reptiles have a mixed heart (oxygenated and deoxygenated blood mixed)

Additional Information

• Birds have 4-chambered hearts made of the right atrium, right ventricle, left atrium, and left ventricle. The division helps for the efficient flow of oxygenated and deoxygenated blood.
• fish have a two-chambered heart, which means that they have only two pumping chambers, the atrium, and the ventricle, but they also have a sinus venosus and a bulbous arteriosus.
• Nematodes don't have hearts, blood vessels, or blood. The fluid in the pseudocoel passively circulates nutrients and other substances throughout the body.

The correct answer is Toxic to human tissues

Key Points Radiotherapy to treat cancer:

• High doses of radiation are used in radiation therapy, also known as radiotherapy, as a cancer treatment to eradicate cancer cells and reduce tumour size.
• As with x-rays of your teeth or shattered bones, radiation is utilised at low doses in x-rays to see inside your body.
• Radiation therapy damages cancer cells' DNA, which either kills them or limits their growth at high dosages.
• Cancer cells that have DNA damage that cannot be repaired either cease proliferating or die.
• When the injured cells expire, the body degrades and eliminates them.
• But too much radiation can damage tissues by changing cell structure and damaging DNA. This can cause serious health problems.

Rocks are an aggregate of one or more minerals held together by chemical bonds. Feldspar and quartz are the most common minerals found in rocks.

Key Points

• Coal is a sedimentary deposit composed predominantly of carbon that is readily combustible. Coal is black or brownish-black, and has a composition that (including inherent moisture) consists of more than 50 percent by weight and more than 70 percent by volume of carbonaceous material.
• Sedimentary rocks are formed by lithification ― consolidation, and compaction of sediments. Hence, they are layered or stratified of varying thicknesses. Example: sandstone, shale, etc.
• Sediments are a result of denudation (weathering and erosion) of all types of rocks. These types of rocks cover 75 percent of the earth’s crust but volumetrically occupy only 5 percent (because they are available only in the upper part of the crust). Ice deposited sedimentary rocks are called till or tillite. Wind-deposited sediments are called loess.

Depending upon the mode of formation, sedimentary rocks are classified into:

1. mechanically formed — sandstone, conglomerate, limestone, shale, loess.
2. organically formed — geyserite, chalk, limestone, coal.
3. chemically formed — limestone, halite, potash.

Hence The rock harder than its original constituent is coal.

Additional Information

• Rocks formed out of the solidification of magma (molten rock below the surface) and lava (molten rock above the surface) and are known as igneous or primary rocks.
• Metamorphism is a process by which recrystallization and reorganization of minerals occur within a rock. This occurs due to pressure, volume, and temperature changes. Gneissoid, slate, schist, marble, quartzite, etc. are some examples of metamorphic rocks.

Many astronomers prefer to use parsecs (abbreviated pc) to measure the distance to stars. This is because its definition is closely related to a method of measuring the distances between stars.

Key Points

• Parsec or parallactic second is a unit of distance.
• It is defined as the distance at which one AU (astronomical unit) subtends an angle of one arc second, and is equal to 3.26 light-years.
• It is the unit of length that is used to measure the large distances of celestial bodies outside the solar system.
• It is obtained by using trigonometry and parallax.
• One parsec is equal to the length of an adjacent side of the imaginary right triangle in space.
• The two dimensions on which this triangle is based are the opposite side (defined as 1 AU-distance from the Earth to the Sun) and the angle (defined as 1 arc-second). Using these two measurements, along with trigonometry, the length of the adjacent side (the parsec) can be determined.

Hence the unit used to express distances to stars and galaxies, used by professional astronomers is parsec.

Additional InformationAstronomers use an effect called parallax to measure distances to nearby stars. Parallax is the apparent displacement of an object because of a change in the observer's point of view.

The Man Who Knew Infinity is a 2015 British biographical drama film about the Indian mathematician Srinivasa Ramanujan, based on the 1991 book of the same name by Robert Kanigel.

Key Points

• Srinivasa Ramanujan was one of India's greatest mathematical geniuses.
• He made substantial contributions to the analytical theory of numbers and worked on elliptic functions, continued fractions, and infinite series.
• Indian mathematician whose contributions to the theory of numbers include pioneering discoveries of the properties of the partition function.

Additional Information

• C.V. Raman was awarded the 1930 Nobel Prize in Physics for his discovery of the Raman effect, in which light that passes through a material is scattered and the wavelength of the scattered light is changed because it has caused an energy state transition in the material's molecules.
• Sir Jagadish Chandra Bose was a biologist, physicist, botanist, and early writer of science fiction. He pioneered the investigation of radio and microwave optics, made significant contributions to plant science, and was a major force behind the expansion of experimental science on the Indian subcontinent.
• Meghnad Saha was an Indian astrophysicist who developed the Saha ionization equation, used to describe chemical and physical conditions in stars. His work allowed astronomers to accurately relate the spectral classes of stars to their actual temperatures.

The correct answer is International Labour Organization.

In 2019, the International Labour Organization – the oldest UN specialized agency had celebrated its 100^th anniversary.

Key Points

ILO:

• Founded on 11 April 1919 under the League of Nations,
• it is the first and oldest specialised agency of the UN.
• it is a United Nations agency whose mandate is to advance social and economic justice through setting international labour standards.
• Headquarters- Geneva, Switzerland
• Director-General - Guy Ryder(United Kingdom)

Hence, International Labour Organization is the specialized agency of the United Nations which celebrated its centenary in 2019:

The correct answer is Sharankumar Limbale

 It was instituted by KK Birla Foundation in 1991, is recognized as the most prestigious and highest literary award in the country.

Key Points

Saraswati Samman 2020

• The Saraswati Samman is an annual award for outstanding prose or poetry literary works in any of the 22 languages of India listed in Schedule VIII of the Constitution of India
• Noted Marathi writer Dr. Sharankumar Limbale received Saraswati Samman, 2020 for his book Sanatan.
• Sanatan is an important social and historical document of the Dalit struggle.

Additional Information

• Noted Sindhi writer Vasdev Mohi was honored with 29^th Saraswati Samman in 2019 for his short stories collection:- Chequebook
• Telugu poet K Siva Reddy was honored with the prestigious Saraswati Samman, in 2018 for his work Pakkaki Ottigilite(Turning Aside While Lying Down)’.
• The 27^th Saraswati Samman 2017 was conferred upon eminent Gujarati poet Sitanshu Yashaschandra for "Vakhar" (Poetry collection)

The correct answer is (a) - (3), (b) - (4), (c) - (1), (d) - (2)

Key Points

Hence the correct matching code is  (a) - (3), (b) - (4), (c) - (1), (d) - (2)

The correct answer is 1, 3 & 4 only

Fundamental Rights are defined as the basic human rights of all citizens which are defined in Part III of the Constitution from Article 12-35.

Key Points

• Fundamental rights:
• These are protected and guaranteed by the constitution.
• These are NOT sacrosanct or absolute means that the parliament can curtail or put reasonable restrictions for a fixed period of time. However, the court has the power to review the reasonability of the restrictions.
• These are justiciable means The constitution allows the person to move directly to the Supreme Court for the reinforcement of his fundamental right as and when they are violated or restricted.
• The Constitution guarantees six fundamental rights to Indian citizens as follows:
• right to equality (Articles 14-18)
• right to freedom (Articles 19-22)
• right against exploitation (Articles 23-24)
• right to freedom of religion (Articles 25-28)
• cultural and educational rights (Articles 29-30),
• right to constitutional remedies (Article 32)

Additional Information

• Right to equal pay for equal work
• There is no fundamental right of Right to equal pay for equal work
• The“Equal pay for equal work” has been enforced by only Directive principles of state policy (DPSP).
• The principle of equal pay for equal work for men and women embodied in Article 39(d) of the Constitution was first considered in Kishori Mohanlal Bakshi vs Union of India in 1962.

​Hence the correct answer is 1, 3 & 4 only