General Science Questions (MCQs) for Competitive Examinations

Notes:
Jhum is a traditional form of shifting cultivation that is common in the North-East of India. Also known as slash and burn agriculture, it is practiced by the tribal groups in Arunachal Pradesh, Meghalaya, Mizoram and Nagaland and the hilly areas of Assam. Jhum involves clearing a piece of land by setting fire or clear felling and using the area for growing crops.

Notes:
Milk is a poor source of ascorbic acid (Vitamin C). It contains about 1 mg ascorbate per 100 g. Even the little Vitamin C is usually destroyed when the milk is heat treated. Milk as a complete food contains most of the esential nutrients except are vitamin C and iron.

Notes:
Blubber is a thick layer of vascularized adipose tissue found under the skin particularly whales inhabiting of Arctic ocean. It’s presence insulate their body from ice cold. The energy stored in blubber includes both proteins (mostly collagen) and fats (mostly lipids). Blubber covers the entire body of animals such as seals, whales, and walruses—except for their fins, flippers, and flukes. Whaling largely targeted the collection of blubber: whalers rendered it into oil in try pots, or later, in vats on factory ships. The oil could serve in the manufacture of soap, leather, and cosmetics. Whale oil was used in candles as wax, and in oil lamps as fuel.

Notes:
Fluorine is the element that is associated with teeth disorder because the presence of sodium fluoride in drinking water at the level of 2ppm may cause mottled enamel in teeth, skeletal fluorosis, and may be associated with cancer and other diseases. However, topically applied fluoride (toothpaste, dental rinses) has been shown to help reduce dental caries.

Notes:
Abscisic acid also called plant stress hormone is responsible for responsible for dormancy of various types. It maintains dormancy in seeds and buds, stimulates the closing of stomata. Gibberellins are responsible for cell division and growth in cell size.

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Bacteriophage refers to any of a group of viruses that infect bacteria. Bacteriophages were discovered independently by Frederick W. Twort in Great Britain (1915) and Felix d’Herelle in France (1917). D’Herelle coined the term Bacteriophage, meaning “bacteria eater”.

Notes:
Anaerobic reactions involve break down of glucose into pyruvic acid, which then reacts to produce lactic acid. As muscle metabolism shifts from aerobic to anaerobic ATP production, lactic acid begins to accumulate in muscles and to appear in the bloodstream. This leads to muscle fatigue with changing pH of muscle cells. C6H12O6 —> 2C3H6O3 + 2ATP

Notes:
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.

Notes:
Mould is a member of the fungi kingdom. Fungi can be defined as a plant without chlorophyll, so it cannot get energy directly from the sun. This means that fungi must use other plants and animals as its food source. This is why bread mould is so common because of the ingredients in bread, it is an excellent source of nutrition for many moulds to grow and thrive.

Notes:
The best-known and most common chromosome abnormality in humans is Down’s syndrome, (Trisomy of 21st pair of chromosome). Down’s syndrome individuals also almost invariably develop Alzheimer’s disease, a form of dementia that is fairly common among the elderly people. People with Down’s syndrome develop this disease in their fourth or fifth decade of life, much sooner than other people. These people are also characterized by presence of webbed neck, Plamers crease, very broad forehead, round face and forked tongue.