General Science Questions (MCQs) for Competitive Examinations

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Glycolysis, part of cellular respiration, is a series of reactions that constitute the first phase of most carbohydrate catabolism, catabolism meaning the breaking down of larger molecules into smaller ones. Glycolysis breaks down glucose and forms pyruvate with the production of two molecules of ATP. The entire process from conversion of glucose to pyruvate is anaerobic that is it does not take place in presence of oxygen.

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The major role of epidermis is to protect all the parts of the plant. Epidermal cells on the aerial parts of the plant often secrete a waxy, water-resistant layer on their outer surface. This aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.

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Calyptrogen is a layer of rapidly dividing cells at the tip of a plant root, from which the root cap is formed. It occurs in grasses and many other plants. The root cap is formed by several layers of cells that envelop the root tip externally. This covering of cells, of which the outermost ones are dead, envelops and protects the growing tip of root.

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The small intestine, the part of the gastrointestinal tract between the stomach and the large intestine, is the main digester and absorber of food. The small intestine has three distinct regions – the duodenum, jejunum, and ileum–that carry out the absorption of nutrients and minerals from food. It converts the food into a semi-solid mass.

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The average adult has a blood volume of roughly 4-5 to 5 litres, which is composed of plasma and several kinds of cells. By volume, the red blood cells constitute about 45% of whole blood, the plasma about 54.3%, and white cells about 0.7%.

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The largest invertebrate is Mollusc. With over 80,000 species, molluscs form the second largest phylum of animals on Earth and range from tiny snails to giant squid and octopuses.

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Motor skills are needed to control the movements of the different muscles in the human body. The frontal lobe plays a large role in voluntary movement. It houses the primary motor cortex which regulates activities like walking. The frontal lobes are also involved in problem solving, spontaneity, memory, language, initiation, judgement, impulse control, etc.

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A biomass is total quantity of weight of the planet that can be classified according to the plants and animals that live in it. Temperature, soil, and the amount of light and water help determine what life exists in a biome.

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Plants, on average, capture only about 0.1 0.4 percent of the solar energy reaching Earth. However, it does not mean that the rest is a “vast untapped reservoir” awaiting man’s exploitation. All biological systems, including crops, follow the second law of thermodynamics when solar energy (a high-energy form) is converted into chemical energy. Plants utilize this chemical energy in the process of building their own tissue.

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Inorganic arsenic found in water is a confirmed carcinogen and is the most significant chemical contaminant in drinking-water globally. Prolonged ingestion of arsenic-containing drinking water is associated with bladder cancer and skin cancer. In addition, cancers of the lung, digestive tract, liver, kidney, and lymphatic and hematopoietic systems are also linked to arsenic exposure.