General Science Questions (MCQs) for Competitive Examinations

Notes:
Eccrine glands, sometimes called merocrine glands, are the major sweat glands of the human body. The specific function of sweat glands is to secrete water upon the surface so that it can cool the skin when it evaporates. The purpose of the glands on the palms and soles, however, is to keep these surfaces damp, to prevent flaking or hardening of the horny layer, and thus to maintain tactile sensibility. The eccrine gland opens out through the sweat pore.

Notes:
Methane (CH4) is a greenhouse gas and causes warming the same way that CO2 does. It absorbs radiation emitted from the surface and re-emits that radiation in all directions with some of the radiation returning to the surface where it is absorbed and converted to heat. In the first two decades after its release, methane is 84 times more potent than carbon dioxide.

Notes:
Common table salt plays a primary role in the processes of digestion and absorption. Salt activates an enzyme in the mouth called salivary amylase. Salt also creates hydrochloric acid. Hydrochloric acid is a very important digestive secretion, which lines the stomach walls.

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Eutrophication is the ecosystem response to the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage. It leads not only to increased levels of nutrients, but increased Biological Oxygen Demand as well following the decay of algal bloom in stagnant water reservoirs.

Notes:
The scientific name of peacock is Pavo Cristatus. It is also known as the Indian blue peafowl, common peafowl, blue peafowl, and blue Indian peafowl. It is a large and brightly coloured bird, is a species of peafowl native to the Indian subcontinent, but introduced in many other parts of the world.

Notes:
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.

Notes:
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.

Notes:
The loose union of structure of the same whorl is called cohesion, but the intimate histological union is called connation. When anthers are fused with each other, the condition is described as syngenesious e.g., Compositae, Lobeliaceae. This fusion is called cohesion. When there is fusion of stamens with petals, they are described as epipetalous e.g., Gamopetale.

Notes:
Peristalsis is the wave of rhythmical contraction, which takes place in the alimentary canal. It is produced by involuntary contraction of circular muscles, which is preceded by a simultaneous contraction of the longitudinal muscle, and relaxation of the circular muscle lining the gut. Peristalsis pushes the food through the alimentary canal.

Notes:
The bark of cinchona tree yields quinine, a white crystalline alkaloid having antipyretic (fever-reducing), anti-malarial, analgesic (painkilling), and anti-inflammatory properties. Quinine was the first effective Western treatment for malaria caused by Plasmodium falciparum.