Search Previous Year Questions

The Correct Answer is Antigen.

Key Points

• Any substance that causes your immune system to produce antibodies against it is known as an antigen.
• This indicates that your immune system has misidentified the substance and is attempting to combat it.
• Material from the environment, such as chemicals, bacteria, viruses, or pollen, may act as an antigen. Antigens can also develop within the body.
• Proteins, peptides (amino acid chains), and polysaccharides (chains of monosaccharides/simple sugars) are all antigens, but lipids and nucleic acids only become antigens when they are mixed with proteins and polysaccharides.
• Vaccines are immunogenic antigens that are administered to a recipient with the aim of inducing the adaptive immune system's memory mechanism of antigens of the pathogen invading the recipient.

Important Points

• Antibodies are large, Y-shaped proteins that the immune system uses to recognize and neutralize foreign objects like bacteria and viruses.
• Enzymes are biological catalysts that are proteins (biocatalysts).
• Hormones are signaling molecules that are transported to distant organs in multicellular organisms to control physiology and/or behavior.

The Correct Answer is Virus. 

Key Points

• The H1N1 virus, also known as swine flu, is a new type of influenza virus that causes symptoms similar to the common flu.
• It was first discovered in pigs, but it is now often spread from person to person.
• When swine flu was first detected in humans and became a pandemic in 2009, it made headlines.
• Pandemics are infectious diseases that spread across the globe or across many continents at the same time.

Important Points

• Bacteria are biological cell types. They make up a wide group of prokaryotic species.
• A fungus (fungi) is a type of eukaryotic organism that includes microorganisms like yeasts and molds, as well as the more well-known mushrooms. These species belong to a different kingdom from the other eukaryotic life kingdoms of plants and animals.
• Tapeworms are intestinal parasites with a tape measure shape.

The Correct Answer is Nitrogen.

Key Points

• Proteins are made up of molecules called amino acids and are found in all living organisms.
• Each amino acid contains four elements: hydrogen, oxygen, nitrogen, and carbon, as well as sulphur in some cases.
• Proteins are macromolecules or massive biomolecules made up of one or more long chains of amino acid residues.
• Proteins play a variety of roles in animals, including catalysing metabolic reactions, DNA replication, reacting to stimuli, giving cells and organisms structure, and transporting molecules from one place to another.
• A polypeptide is a linear sequence of amino acid residues.
• At least one long polypeptide can be found in a protein. Antoine Fourcroy and others identified proteins as a distinct class of biological molecules in the eighteenth century, based on their ability to coagulate or flocculate when exposed to heat or acid.

The Correct Answer is Energy​.

Key Points 

• Heat is a source of energy, according to the First Law of Thermodynamics, and thermodynamic processes are thus subject to the principle of energy conservation. Heat energy cannot be produced or lost in this way.
• It can, however, be moved from one place to another and transformed into and out of different types of energy.
• Thermodynamics is a branch of physics concerned with the interactions of heat and other sources of energy.
• According to the First Rule, a system's internal energy must be equal to the work that is being done on it, plus or minus the heat that flows in and out of it, and any other work that is being done on it.

Important Points

• Entropy is a physical property of a thermodynamic system, according to the second law of thermodynamics.
• Regarding the properties of closed systems in thermodynamic equilibrium**, the third law of thermodynamics** notes as follows: As a system's temperature gets closer to absolute zero, its entropy reaches a constant value.

The Correct Answer is Gammexane.

In view of environmental problems, the use of Gammexane has been reduced.

Key Points

• Gammaxene (Lindane, gamma-hexachlorocyclohexane (-HCH), is an organochlorine chemical and isomer of hexachlorocyclohexane that has been used as lice and scabies medicinal remedy.
• Lindane is a neurotoxin that interferes with GABA neurotransmitter activity by binding to the picrotoxin binding site on the GABA receptor-chloride channel complex.
• Lindane is a carcinogen that affects the nervous system, liver, and kidneys in humans.
• The World Health Organization classifies lindane as "moderately dangerous," and the Rotterdam Convention on Prior Informed Consent restricts and regulates its international trade.

Additional Information

• The organophosphate phorate is used as an insecticide and acaricide.
• Endosulfan is an off-patent organochlorine insecticide and acaricide that is currently being phased out around the world. Endo and Exo are the two isomers that are often referred to as I and II.
• Mancozeb is a non-systemic dithiocarbamate agricultural fungicide that has a multi-site, contact-protective action. It's made up of maneb and zineb, two other dithiocarbamates.

The Correct Answer is Carbon dioxide.

Key Points 

• CO₂ fire extinguishers contain pure carbon dioxide, which is a residue-free extinguisher.
• Recommended for use on live electrical equipment and suitable for Class B flammable liquid fires (petrol, tar, solvents).
• In 1924, the Walter Kidde Company invented the carbon dioxide (CO₂) extinguisher in response to Bell Telephone's request for an electrically non-conductive chemical for extinguishing previously difficult-to-extinguish fires in telephone switchboards.
• Carbon dioxide works to put out fires by displacing oxygen. It was once thought that it worked by cooling the fire, but this effect is insignificant in most cases.

Important Points

• Sand extinguishers are used to put out flammable metal fires (class D fires) by actually smothering them.
• Water fire extinguishers penetrate burning materials, providing a cooling effect and preventing reignition. They are ideal for use on class A solid combustible fires (wood, paper, fabrics, coal).

The Correct Answer is Ethylene.

Key Points

• Ethylene, also known as the "fruit-ripening hormone," is a gas. Throughout its lifecycle, every fruit produces a certain amount of ethylene.
• When fruit begins to ripen, however, ethylene levels rise dramatically.
• Fruits can be divided into two classes based on how they react to ethylene during maturation.
• The climacteric fruits are the first category, with ripening followed by an ethylene explosion.
• The non-climacteric fruits are those whose ethylene production does not increase as the fruit ripens.

Important Points 

• Auxins encourage stem elongation while inhibiting lateral bud development (maintains apical dominance). The stem, buds, and root tips all contain them.
• Kinetin is a type of cytokine. Cytokinins are substances that help plants grow. Kinetin is a substance that is used in the production of pharmaceuticals.

The correct answer is Oils.

Key Points

• The sunflower seed is the sunflower's fruit (Helianthus annuus).
• Sunflower seeds come in three varieties: linoleic (the most common), high oleic, and sunflower oil seeds.
• Monounsaturated, saturated, and polyunsaturated fats are all different in each type. The material in this article is all about linoleic acid.
• Protein (42 percent DV), dietary fiber (36 percent DV), many B vitamins (23–129 percent DV), and vitamin E are all abundant in the seeds (20 percent or higher of the Daily Value, DV) (234 percent DV).
• Dietary minerals such as magnesium, manganese, phosphorus, iron, and zinc (40–94 percent DV) are also abundant in these seeds.

The Correct Answer is Distance.

Key Points 

• The parsec is a unit of length used to measure vast distances between astronomical objects outside the Solar System.
• It is roughly equivalent to 3.26 light-years or 206,000 astronomical units, or 30.9 trillion kilometers (19.2 trillion miles).
• Proxima Centauri, the closest star, is around 1.3 parsecs (4.2 light-years) away from the Sun.
• The majority of stars visible in the night sky to the naked eye are within 500 parsecs of the Sun.
• The term parsec, derived from the parallax of one arcsecond, was invented by British astronomer Herbert Hall Turner in 1913 to make astronomical distance measurements easier for astronomers using only raw observational data.

Important Points

The correct answer is Analytical Engine. 

Key Points

• Analytical Engine generally considered the first computer, designed and partly built by the English inventor Charles Babbage in the 19^th century (he worked on it until his death in 1871).
• While working on the Difference Engine, a simpler calculating machine commissioned by the British government, Babbage began to imagine ways to improve it.
• Chiefly he thought about generalizing its operation so that it could perform other kinds of calculations.
• By the time funding ran out for his Difference Engine in 1833, he had conceived of something far more revolutionary: a general-purpose computing machine called the Analytical Engine.
• The Analytical Engine was to be a general-purpose, fully program-controlled, automatic mechanical digital computer.
• It would be able to perform any calculation set before it.
• The machine was designed to consist of four components: the mill, the store, the reader, and the printer. These components are the essential components of every computer today.

Additional Information

• Abacus:
• Abacus, plural abaci or abacuses, calculating device, probably of Babylonian origin, that was long important in commerce.
• It is the ancestor of the modern calculating machine and computer.
• The earliest “abacus” likely was a board or slab on which a Babylonian spread sand so he could trace letters for general writing purposes.
• The word abacus is probably derived, through its Greek form abakos, from a Semitic word such as the Hebrew ibeq (“to wipe the dust”; noun abaq, “dust”).
• The abacus, generally in the form of a large calculating board, was in universal use in Europe in the Middle Ages, as well as in the Arab world and in Asia.
• It reached Japan in the 16^th century. The introduction of the Hindu-Arabic notation, with its place value and zero, gradually replaced the abacus, though it was still widely used in Europe as late as the 17^th century and survives today in the Middle East, China, and Japan; an expert practitioner can compete against many modern mechanical calculating machines.
• Calculator:
• Calculator, machine for automatically performing arithmetical operations and certain mathematical functions.
• Modern calculators are descendants of a digital arithmetic machine devised by Blaise Pascal in 1642.
• Later in the 17^th century, Gottfried Wilhelm Leibniz created a more advanced machine, and, especially in the late 19^th century, inventors produced calculating machines that were smaller and smaller and less and less laborious to use.
• In the early decades of the 20^th century, desktop adding machines and other calculating devices were developed. Some were key-driven, others required a rotating drum to enter sums punched into a keyboard, and later the drum was spun by an electric motor.
• A central processing unit (CPU):
• The central processing unit (CPU), the principal part of any digital computer system, generally composed of the main memory, control unit, and arithmetic-logic unit.
• It constitutes the physical heart of the entire computer system; to it is linked various peripheral equipment, including input/output devices and auxiliary storage units.
• In modern computers, the CPU is contained on an integrated circuit chip called a microprocessor.
• The control unit of the central processing unit regulates and integrates the operations of the computer.
• It selects and retrieves instructions from the main memory in proper sequence and interprets them so as to activate the other functional elements of the system at the appropriate moment to perform their respective operations.