General Science Questions (MCQs) for Competitive Examinations

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Measles is an infectious disease caused by the rubeola virus. It is transmitted via droplets from the nose, mouth or throat of infected persons. It remains an important cause of death among young children globally, despite the availability of a safe and effective vaccine.

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The daily salt intake of camels is eight times that of a typical cow or sheep. Yet, surprisingly, they do not develop high blood pressure. Similarly, their blood sugar levels are twice those of other cud chewing animals; still they do not develop diabetes.

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Blood pressure is usually expressed in terms of the systolic (maximum) pressure over diastolic (minimum) pressure and is measured in millimetres of mercury (mm Hg). It is one of the vital signs along with respiratory rate, heart rate, oxygen saturation, and body temperature. Normal resting blood pressure in an adult is approximately 120/80 mm Hg.

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According to the K+ ion theory the guard cells absorb K+ ions from the cells around them as they produce ATP (due to photosynthesis) and become hypertonic. This leads to absorption of water from nearby cells by endosmosis due to which the guard cells become turgid and the stomata opens. Decreasing light intensity and photosynthesis causes Stomatal closing.

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The National Institute of Mental Health and Nuro- Sciences is a premier medical institution located in Bengaluru, India. NIMHANS is the apex centre for mental health and neuroscience education in the country, the institute operates autonomously under the Ministry of Health and Family Welfare.

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Chlorophyll, a photo-receptive pigment, allows plants to absorb sunlight. Chlorophyll is a chlorine pigment, which is structurally similar to and produced through the same metabolic pathway as other porphyrin pigments such as heme. At the center of the chlorine ring is a magnesium ion. The molecular formula of C55H70O6N4 Mg. Hence, chlorophyll as a pigment lacks calcium.

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Fertilization in plants is not directly influenced by sunlight. Fertilization occurs after pollination, when pollen grains land on the stigma of a flower of the same species. During this time, a series of events take place leading to the formation of seeds. However, none of these event is affected by presence or absence of light.

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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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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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Metamorphosis is a process by which animals undergo extreme, rapid physical changes some time after birth. Commonly known examples of metamorphosis include the process undergone by most insects, and the transformation of tadpoles into frogs. Hormones called molting and juvenile hormones, which are not species specific, apparently regulate the changes.