General Science Questions (MCQs) for Competitive Examinations

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Cell theory was first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann. They stated that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells.

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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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Water catchment areas such as forests are continually being destroyed through deforestation to pave way for human settlement. This problem has been brought about by rapid population increase. As a result, there is not enough rain thus causing water shortage.

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An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach. When excessive amounts of acids are produced in the stomach the natural mucous barrier that protects the lining of the stomach can damage the esophagus in people with acid reflux. Antacids contain alkaline ions that chemically neutralize stomach gastric acid, reducing damage and relieving pain.

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Insect and bird wings are analogous structures but not homologous structures. They are externally similar in appearance and function (i.e. for flying), but have dissimilar origin and developmental plan.

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G. Haberlandt, a German botanist, in 1902 cultured fully differentiated plant cells isolated from different plants. This was the very first step for the beginning of plant cell and tissue culture. Further contributions were made by the Cell Doctrine which admitted that a cell is capable of showing totipotency. In India, the credit for detailed working on tissue culture goes to P. maheshwari.

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A typical adult human skeleton consists of 206 bones. Individuals may have more or fewer bones than this owing to anatomical variations. These include: 22 Cranial and Facial Bones; 6 Ear Bones; 1 Throat Bone; 4 Shoulder Bones; 25 Chest Bones; 26 Vertebral Bones; 6 Arm and Forearm Bones; 54 Hand Bones; 2 Pelvic Bones; 8 Leg Bones; and 52 Foot Bones.

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Odontology is the study of the structure, development, and abnormalities of the teeth. Forensic dentistry or forensic odontology is the proper handling, examination and evaluation of dental evidence, which can be presented in the interest of justice.

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The human body requires more calcium than any other mineral. At least 99% of the calcium is found in the bones and teeth, giving them strength and rigidity.

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Weil’s disease is a severe form of leptospirosis, a type of infection caused by Leptospira bacteria. The classic form of severe leptospirosis is known as Weil’s disease, which is characterized by liver damage (causing jaundice), kidney failure, and bleeding.