General Science Questions (MCQs) for Competitive Examinations

Notes:
An analgesic or painkiller is any member of the group of drugs used to achieve analgesia, relief from pain. Analgesic drugs act in various ways on the peripheral and central nervous systems. They are distinct from anaesthetics, which temporarily affect, and in some instances completely eliminate, sensation.

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.

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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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Anaemia is a condition that develops when blood lacks enough healthy red blood cells or haemoglobin. The three main types of Anaemia are due to blood loss, decreased red blood cell production, and increased red blood cell breakdown. Causes of decreased production include iron deficiency, a lack of vitamin B12, thalassemia, and a number of neoplasms of the bone marrow.

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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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Grasshoppers are a group of insects belonging to the suborder Caelifera. They have three main body parts, the head, the thorax and the abdomen. They breathe through a series of holes called ‘spiracles’ which are located along the sides of the body. On grasshoppers, there is a large round disc on the first segment next to the thorax. It is called a tympanum and is the grass-hopper’s ear.

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Beriberi is a disease caused by a vitamin B1 (thiamine) deficiency. There are two types of the disease: wet beriberi and dry beriberi. Wet beriberi affects the heart and circulatory system. In extreme cases, wet beriberi can cause heart failure. Dry beriberi damages the nerves and can lead to a loss of muscle strength and eventually, muscle paralysis.

Notes:
A vein is an elastic blood vessel that transports blood from various regions of the body to the heart. Veins are components of the cardiovascular system, which circulates blood to provide nutrients to the cells of the body. Veins can be categorized into four main types: pulmonary, systemic, superficial, and deep veins.

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The organs which have different basic structure and origin abut are similar in their appearance and functioning, are called analogous organs. An example of analogous organs are the wings of insects, bats and birds that evolved independently in each lineage separately after diverging from an ancestor without wings.

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The deficiency of magnesium leads to yellowish green blotch near the base of the leaf between the midrib and the outer edge (chlorosis). The yellow area enlarges until the only green remaining is at the tip and base of the leaf as an inverted V-shaped area on the midrib.