General Science Questions (MCQs) for Competitive Examinations

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Chlorargyrite is the mineral form of silver chloride (AgCl). It is also known as cerargyrite and, when weathered by desert air, as horn silver. Silver chloride is formed by the disappearance of the initial silver oxide layer.

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According to de Broglie, every object in motion has a wave character. As per de Broglie’s relation, mass and wavelength are inversely proportional to each other.

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The Moon has been bombarded with large quantities of Helium-3 by the solar wind. It is thought that this isotope could provide safer nuclear energy in a fusion reactor, since it is not radioactive and would not produce dangerous waste products.

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Flowers emit fragrance to attract pollinators which are mainly insects. The fragrance plays a prominent role in the localization and selection of flowers by insects, especially moth-pollinated flowers, which are detected and visited at night. If they have become infested with herbivores like caterpillars, they attract beneficial insects like parasitic wasps with the help of scent signals from their leaves.

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Cyanobacteria, also known as blue green algae, are single-celled and belong to the family of Prokaryotes. That means, they do not have a well defined cell nucleus. The ability of cyanobacteria to perform oxygenic photosynthesis is thought to have converted the early reducing atmosphere into an oxidizing one, which dramatically changed the composition of life forms on Earth by stimulating biodiversity and leading to the near-extinction of oxygen-intolerant organisms.

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Based on the dividing capacity of the tissues, various plant tissues can be classified as growing or meristematic tissue and permanent tissue. Meristem is a type of tissue system in plants, composed of a mass of undifferentiated cells and their primary function is to take part in the growth of plants. Permanent tissues are differentiated tissues doing specific functions such as conduction, providing mechanical support or carrying out photosynthesis etc.

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In menstrual cycle 19-21 days stands for the fertilizing period also called danger period. After ovulation on 14th day chances of contraption are at their highest with well developed endometrium for implantation. This is the time in the menstrual cycle when progesterone should be at its peak for the month and when estrogen should be at the height of its luteal plateau.

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Crown gall is a disease caused by the bacterium Agrobacterium tumefaciens (synonym Rhizobium radiobacter), which enters the plant through wounds in roots or stems and stimulates the plant tissues to grow in a disorganized way, producing swollen galls. As the disease progresses, plants lose vigour and may eventually die. In science of Biotechnology, it is considered as natural engineer.

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Sphygmomanometer an instrument for measuring blood pressure. It typically consists of an inflatable rubber cuff which is applied to the arm and connected to a column of mercury next to a graduated scale, enabling the determination of systolic and diastolic blood pressure by increasing and gradually releasing the pressure in the cuff. The sphygmomanometer was invented by Samuel Siegfried Karl Ritter von Basch in 1881.

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Changes in pH which can accompany metabolic process such as respiration (aerobic glycolysis for example) can alter the conformation of an enzyme and hence enzyme activity such as salivarya mylase is effective in neutral condition, pepsin in acidic condition l.5 (less than pH 7) and trypsin in basic condition (more than pH 7).