General Science Questions (MCQs) for Competitive Examinations

Notes:
The carat is the common unit used to describe the mass of a gem. A 1-carat diamond, for example, has a mass of 0.20 g. The karat is the common unit used to describe the purity of a precious metal, such as gold. A 24-karat gold ring is as pure as can be. A gold ring that is 50 % pure is 12 karat.

Notes:
Nickel, Platinum and Darmstadtium belongs to Group number 10 whereas element Roentgenium is placed in group number 11.

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All metal carbonates and hydrogen carbonates react with acids to give a corresponding salt, carbon dioxide and water. Limestone, chalk and marble are different forms of calcium carbonate.

Notes:
Edible seaweed products have been consumed in many Asian countries. Edible seaweeds accumulate iodine from seawater and are therefore a good dietary source of iodine. Adequate consumption of seaweed can eliminate iodine deficiency disorders, but excessive iodine intake is not good for health. The recommended dietary reference intake of 0.15 mg/d and 0.14 mg/d for iodine has been established in the United States and Taiwan, respectively. Seaweed is an excellent source of iodine. However, the amount it contains depends on the species. Kombu kelp offers the highest amount of iodine, with some varieties containing nearly 2,000% of the daily value in one gram. Seaweed is a source of iodine, necessary for thyroid function and to prevent goitre. However, an excess of iodine is suspected in the heightened cancer risk in Japanese who consume a lot of the plant, and even bigger risks in post-menopausal women.

Notes:
Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae (whites of the eyes), and other mucous membranes caused by hyperbilirubinemia. Concentration of bilirubin in blood plasma does not normally exceed 1 mg/dL (>17?mol/L). A concentration higher than 1.8 mg/ dL (>30?mol/L) leads to jaundice. Jaundice is often seen in liver disease such as hepatitis or liver cancer.

Notes:
Taenia is a genus of tapeworm that includes some important parasites of livestock. Members of the genus are responsible for taeniasis and cysticercosis in humans. There are more than 100 species recorded. They are morphologically characterized by a ribbon-like body composed of a series of segments called proglottids with proximal mouth called scolex.

Notes:
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.

Notes:
Panthera pardus is the scientific name of leopard, one of the five “big cats” in the genus Panthera. It is a member of the family Felidae with a wide range in sub-Saharan Africa and parts of Asia. It belongs to the Chordata phylum, Mammalia class and Carnivora order.

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Growth hormone or somatotropin, also known as human growth hormone in its human form, is a peptide hormone that stimulates growth, cell reproduction and cell regeneration in humans and other animals. It is thus important in human development.

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Utricularia (also called bladderworts) is a genus of insectivorous plants. They occur in fresh water and wet soil as terrestrial or aquatic species. All Utri cularia are carnivorous and capture small organisms by means of bladder-like traps. Aquatic species feed on protozoa and rotifers swimming in water-saturated soil’ while terrestrial species feed on water fleas (Daphnia), nematodes and even fish fry, mosquito larvae and young tadpoles.