General Science Questions (MCQs) for Competitive Examinations

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The central nervous system (CNS) controls most functions of the body and mind. It consists of two parts: the brain and the spinal cord. Both the brain and spinal cord are protected by a three-layered covering of connective tissuecalled the meninges.

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According to the Red list of 2012, Ganges River Dolphin is one of critically endangered species in India. Endangered species in India comprise large varieties of rare species of wild animals, aquatic animals and insects.

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Vitamin D is essential in helping the body absorb and use calcium; in fact, the body cannot absorb calcium at all without some vitamin D. Vitamin D helps our intestines absorb calcium from the food we eat and helps build stronger bones.

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Cause of night blindness is a deficiency of retinol, or vitamin A, found in fish oils, liver, dairy products, vegetable and fruits yellow in colour. Nyctalopia also called “Night Blindness” is a condition making it difficult or impossible to see in relatively dim light. To over come deficiency of vitamin-A, one needs to feed of food products rich in carotene which is used in synthesis of vitamin-A is liver.

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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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Cinnamon is a spice obtained from the inner bark of several tree species from the genus Cinnamomum. Cinnamon is used mainly as an aromatic condiment and flavoring additive in a wide variety of cuisines. The aroma and flavor of cinnamon derive from its essential oil and principal component, cinnamaldehyde, as well as numerous other constituents, including eugenol.

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The vascular tissue system consists of the complex tissues, xylem and phloem, which constitute discrete conducting strands called vascular bundles. Gymnosperms are the vascular plants where seeds are not enclosed within an ovary (opposite to an angiosperm or flowering plants where seeds are enclosed by mature ovaries or fruits). Collateral vascular bundle is the most common type of vascular bundle in the stems and leaves of angiosperms and gymnosperms. Here xylem and phloem remain side by side arranged on the same radius.

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In an autosomal dominant disorder, the mutated gene is a dominant gene located on one of the nonsex chromosomes (autosomes). The early-onset form of Alzheimer disease is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person inherits the altered gene from one affected parent.

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The first observations of intracellular structures that probably represented mitochondria were published in the 1840s. Richard Altmann, in 1890, established them as cell organelles and called them “bioblasts”. The term “mitochondria” was coined by German microbiologist Carl Benda in 1898.

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Sponges are sedantric, diploblastic, asymmetrical animals, once considered plants. They are characterized by the water canal system with pores called the ostia and osculum. They are also known to posses the multipurpose cells called chanocytes.