General Science Questions (MCQs) for Competitive Examinations

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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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Keratin is a family of fibrous structural proteins involved in making up the outer layer of human skin. It is also the key structural component of hair and nails. Cells in the epidermis contain a structural matrix of keratin, which makes this outermost layer of the skin almost waterproof, and along with collagen and elastin, gives skin its strength. It also makes up fish scales and crustacean shells, bird feathers and beaks, animal horns and hooves.

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Chickenpox, also known as varicella, is a highly contagious infection caused by the varicella zoster virus. The disease results in a characteristic skin rash that forms small, itchy blisters, which eventually scab over. It is an airborne disease which spreads easily through the coughs and sneezes of an infected person.

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Typhoid is a common worldwide bacterial disease transmitted by the ingestion of food or water contaminated with the feces of an infected person, which contain the bacterium Salmonella enterica subsp. enterica, serovar Typhi.

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The membranes of chill sensitive plants have about a 2 :1 ratio of unsaturated to saturated fatty acids. It has been seen that the proportion of unsaturated membrane fatty acids increases and the critical temperature decreases so that chill-sensitive plants are more acclimitized to low temperatures.

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The brain’s limbic system controls emotional expression through the hypothalamus, which has control over the body’s emotional responses systems. The hypothalamus is responsible for regulating hunger, thirst, response to pain, levels of pleasure, sexual satisfaction, anger and aggressive behavior, etc. It also regulates pulse, blood pressure, breathing, and arousal in response to emotional circumstances.

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Pulses are part of the legume family, but the term “pulse” refers only to the dried seed. Dried peas, edible beans, lentils and chickpeas are the most common varieties of pulses. The term “legume” refers to the plants whose fruit is enclosed in a pod. Other well-known legumes include alfalfa, clover, fresh peas, lupins, mesquite, soy and peanuts.

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Carbon monoxide poisoning can be cured by exposing the affected person to fresh oxygen. It is because CO posoning leads to oxygen starvation of body cells. This therapy involves breathing pure oxygen in a chamber in which the air pressure is about two to three times higher than normal. This speeds the replacement of carbon monoxide with oxygen in your blood. Hyperbaric oxygen therapy may be used in cases of severe carbon monoxide poisoning.

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Bacteria are the most abundant organisms which play important role in the decomposition of organic matter. Majority of bacteria involved in decomposition of organic matter are heterotrophs and autotrophs are least in proportion which are not directly involved in organic matter decomposition.

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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).