Biology MCQs

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Based on the dividing capacity of the tissues, various plant tissues can be classified as growing or meristematic tissue and permanent tissue. Meristem is a type of tissue system in plants, composed of a mass of undifferentiated cells and their primary function is to take part in the growth of plants. Permanent tissues are differentiated tissues doing specific functions such as conduction, providing mechanical support or carrying out photosynthesis etc.

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The swim bladder is an internal gas-filled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming. The cartilaginous fish (e.g. sharks and rays) split from the other fishes about 420 million years ago and lack both lungs and swim bladders, suggesting that these structures evolved after that split.

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A scavenger is an organism that mostly consumes decaying biomass, such as meat or rotting plant material. Fungi are called as scavengers of earth as they decompose waste.

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Strontium-90 is a radioactive isotope of strontium produced by nuclear fission. Used mostly in weapons and nuclear power plants, poisoning usually occurs through accidental ingestion. Studies have also linked strontium-90 to various forms of skin cancer.

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Palynology is the scientific discipline concerned with the study of plant pollen, spores, and certain microscopic planktonic organisms, by this way diatom, in both living and fossil form. It is associated with the plant sciences as well as with the geologic sciences, notably those aspects dealing with stratigraphy, historical geology, study of organic microfossils (palynomorphs) extracted from ancient coals, paleontology and archaeology.

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The red, orange and yellow colours of leaf are due to carotenoids contained in chromoplasts. When the green chlorophyll in leaves diminishes, the yellow pigments that already exist become dominant and give their color to the leaves.

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There are three meristematic layers in plants which consist of three sets of initials known as histogen. Dermatogen is the outermost layers, the cells of which divide anticlinally and give rise to the epidermis. Periblem and Plerome are the other two histogen.

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Vitamin B12 contains cobalt. Deficiency of Vitamin B12 causes pernicious anaemia and inflammation of tongue and mouth. Vitamin A, Vitamin C and Vitamin E are anti-oxidants.

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Although sea stars (star fish) are benthoic i.e. live underwater and are commonly called “starfish,” yet they are not fish. They belong to phylum Echinodermata whose members are exclusively marine and benthsoc with great power of repeneration are characterized by water vascular system.

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Syrinx is the name for the vocal organ of birds. Located at the base of a bird’s trachea, it produces sounds without the vocal cords of mammals. The sound is produced by vibrations of some or all of the membrana tympaniformis (the walls of the syrinx) and the pessulus caused by air flowing through the syrinx.