General Science Questions (MCQs) for Competitive Examinations

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The nephron is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.

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Linseed are the seeds of the flax plant, which are the source of linseed oil and linseed cake. Flax is a member of the genus Linum in the family Linaceae. Linseed is one of the most potent sources of omega- 3 fatty acids found in nature.

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Anaemia is a condition that develops when blood lacks enough healthy red blood cells or haemoglobin. The three main types of Anaemia are due to blood loss, decreased red blood cell production, and increased red blood cell breakdown. Causes of decreased production include iron deficiency, a lack of vitamin B12, thalassemia, and a number of neoplasms of the bone marrow.

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Methane (CH4) is a greenhouse gas and causes warming the same way that CO2 does. It absorbs radiation emitted from the surface and re-emits that radiation in all directions with some of the radiation returning to the surface where it is absorbed and converted to heat. In the first two decades after its release, methane is 84 times more potent than carbon dioxide.

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Insulin is a hormone secreted by the pancreas that is important for metabolism and utilization of energy from the ingested nutrients – especially glucose. It keeps our blood sugar level from getting too high (hyperglycemia) or too low (hypoglycemia). The pancreas is a glandular organ in the digestive system and endocrine system of vertebrates.

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Plaster of Paris is a plaster made by calcining gypsum.
CaSO4•1/2?H2?O.
It can be used to impregnate gauze bandages to make a sculpting material called modroc. It is used to make classic plaster orthopedic casts to protect limbs with broken bones.

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Detoxification is the physiological or medicinal removal of toxic substances from a living organism which is mainly carried out by the liver. It breaks down or transforms substances like ammonia, metabolic waste, drugs, alcohol and chemicals, so that they can be excreted. The liver filter is designed to remove toxic matter such as dead cells, microorganisms, chemicals, drugs and particulate debris from the bloodstream.

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Fructose, or fruit sugar, is a simple ketonic monosaccharide found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is a 6-carbon polyhydroxyketone with chemical formula of C6H12O6.

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Alveoli are an important part of the respiratory system whose function it is to exchange oxygen and carbon dioxide molecules to and from the bloodstream. These tiny, balloon-shaped air sacs sit at the very end of the respiratory tree and are arranged in clusters throughout the lungs. Alveoli are tiny balloon shaped structures and are the smallest passageway in the respiratory system.

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Most of Earth’s oxygen comes from tiny ocean plants – called phytoplankton – that live near the water’s surface and drift with the currents. Like all plants, they photosynthesize – that is, they use sunlight and carbon dioxide to make food. Scientists believe that phytoplankton contribute between 50 to 85 percent of the oxygen in Earth’s atmosphere (National Geographic).