General Science Questions (MCQs) for Competitive Examinations

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The transport of water, nutrients and other substances from one part of a plant to another is called translocation. While, phloem transports synthesized food from the leaves to the rest of the plant body; water and minerals are transported from the roots upwards through the xylem tubes.

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The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the “master gland” of the body, it produces many hormones that travel throughout the body, directing certain processes or stimulating other glands to produce other hormones.

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AIDS virus destroys the T-cells inside of the immune system. T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity.

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Bone is a composite of proteins such as collagen and minerals such as calcium. Calcium phosphate is the major component of bones and teeth. Except for small portions of the inner ear, all hard tissues of the human body are formed of calcium phosphate. Collagen gives the bones a soft framework, while calcium makes them hard and strong.

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DNA profiling (genetic finger printing) is a technique employed by forensic scientists to assist in the identification of individuals by their respective DNA profiles. DNA profiles are encrypted sets of numbers that reflect a person’s DNA makeup, which can also be used as the person’s identifier. Each individual has unique VNTR numbers and pattern except maternal twins.

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Water is transported through the plant in Xylem vessels, these begin in the roots and end in the leaves of the plant. Water is transported through a combination of “Transpirational pull” and capillary action that produces root pressure.

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Deciduous trees and shrubs are plants that annually lose their leaves at the end of each growing season; usually during the winter, but can also occur during a dry season in warm climates. Common examples of deciduous trees include oak, maple, and hickory trees. Oak trees are characteristic deciduous trees that lose their leaves in the fall and regrow them in the spring.

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Tuberculosis (TB) is an infectious disease of the lungs. It is typically caused by bacteria called Mycobacterium tuberculosis. The common cold is a viral infectious disease of the upper respiratory tract that primarily affects the nose. AIDS (acquired immunodeficiency syndrome) is a syndrome caused by a virus called HIV (human immunodeficiency virus). Dengue fever is a mosquito-borne tropical disease caused by the dengue virus.

Notes:
All mammals and birds are warm-blooded while all reptiles, arachnids, insects, amphibians, fish are coldblooded. Therefore, all primates (such as humans, apes, and monkeys), cats (tigers, cheetahs, and domestic cats), rodents (rats, beavers, and chipmunks), marsupials (kangaroo), weasels (badgers and meerkats), monotremes (platypuses), sea mammals (whales, seals, walruses, manatees, and dolphins), dogs, pigs, and elephants are warm-blooded.

Notes:
Salt, fat and leavening agents such as yeast and baking soda are common ingredients, though bread may contain other ingredients also. Yeast plays an important role in bread-making. It ferments and grows when combined with “food” such as flour and/ or sugar, and warmed. Carbon dioxide is produced and trapped in the dough as tiny air bubbles which make the bread rise during cooking and give it its characteristic texture.