Biology MCQs

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Herbert W. Boyer and Stanley N proposed rDNA technology. Recombinant DNA (rDNA) is a technology that uses enzymes to cut and paste together DNA sequences of interest.

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The thyroid gland is one of the largest endocrine glands in the human body which is found in the neck. It controls how quickly the body uses energy, makes proteins, and controls how sensitive the body is to other hormones.

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Nitrogen-fixing bacteria are microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen. Rhizobium is one such bacteria that is associated with leguminous plants (e.g., various members of the pea family). It invades the root hairs of host plants and convert free nitrogen to ammonia, which the host plant utilizes for its development.

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The principal chemical component of vegetable fibres is cellulose, with varying amounts of lignin and hemicelluloses also usually present; thus, the fibres are also referred to as cellulosic or lignocellulosic. Examples include cotton, hemp, jute, flax, ramie, sisal, bagasse, and banana. Vegetable fibres are usually stiffer but less tough than synthetic fibres.

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The Rock Dove (Columba livia) or Rock Pigeon, is a member of the bird family Columbidae (doves and pigeons). In common usage, this bird is often simply referred to as the “pigeon”. The species includes the domestic pigeon (including the fancy white pigeon).

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Cecum is a pouch connected to the junction of the small and large intestines. It is a large tube-like structure in the lower abdominal cavity that receives undigested food material from the small intestine and is considered the first region of the large intestine. It is separated from the ileum (the final portion of the small intestine) by the ileocecal valve (also called Bauhin valve). The main functions of the cecum are to absorb fluids and salts that remain after completion of intestinal digestion and absorption and to mix its contents with a lubricating substance, mucus.

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Organ donation is the process of donating organs or biological tissue to a living recipient, who is in need of a transplant. The eyes of a dead person can be used only if they are taken out within 6 hrs of death. Only corneal blinds can be benefitted through this process not other Blinds.

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Arrector pili is a microscopic band of muscle tissue which connects a hair follicle to the dermis. ? When stimulated, the arrector pili will contract and cause the hair to become more perpendicular to the skin surface (stand on end), known colloquially as goose bumps.

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White lung shows acute lung injury characterized by coughing inflammation of the lungs which become stiff and fibrous and cannot exchange oxygen. It occurs among persons exposed to irritants such as corrosive chemical vapor or ammonia or chlorine etc. Brown lung, or bysinnois, similar to black lung (pneumoconiosis) and white lung (asbestosis) disease among coal miners and shipyard workers and workers in textile industry exposed to asbestos are well known occupational hazards.

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The cerebrum is the largest part of the human brain, making up about two-thirds of the brain’s mass. It has two hemispheres, each of which has four lobes: frontal, parietal, temporal and occipital. It is involved in several functions of the body including: determining intelligence; determining personality; thinking, perceiving, interpretation of sensory functions, etc.