General Science Questions (MCQs) for Competitive Examinations

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Haemophilia is a group of hereditary genetic disorders that impairs the body’s ability to control blood clotting, which is used to stop bleeding when a blood vessel is broken. It is a sex-linked recessive disorder which is more likely to occur in males than females.

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Tachycardia is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 80 beats per minute is accepted as tachycardia in adults. A healthy adult heart normally beats 60 to 100 times a minute when a person is at rest. Tachycardia occurs when an abnormality in the heart produces rapid electrical signals.

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Green is the least effective color of light in driving photosynthesis, the process of converting light energy into chemical energy. Photosynthesis occurs in plants and algae using chlorophyll, and because chlorophyll reflects rather than absorbs green light, green light cannot be used in the photosynthetic process.

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Swim bladder is also known as air bladder for fishes. It is a buoyancy organ possessed by most bony fishes. The swim bladder is located in the body cavity and is derived from an out-pocketing of the digestive tube. It contains gas (usually oxygen) and functions as a hydrostatic, or ballast, organ, enabling the fish to maintain its depth without floating upward or sinking. It also serves as a resonating chamber to produce or receive sound.

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Glycolysis is the first of the main metabolic pathways of cellular respiration to produce energy in the form of ATP. Through two distinct phases, the six-carbon ring of glucose is cleaved into two three-carbon sugars of pyruvate through a series of enzymatic reactions. Overall, the process of glycolysis produces a net gain of two pyruvate molecules, two ATP molecules, and two NADH molecules for the cell to use for energy.

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The nephron is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.

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Eutrophication is the ecosystem response to the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage. It leads not only to increased levels of nutrients, but increased Biological Oxygen Demand as well following the decay of algal bloom in stagnant water reservoirs.

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Grasshoppers are a group of insects belonging to the suborder Caelifera. They have three main body parts, the head, the thorax and the abdomen. They breathe through a series of holes called ‘spiracles’ which are located along the sides of the body. On grasshoppers, there is a large round disc on the first segment next to the thorax. It is called a tympanum and is the grass-hopper’s ear.

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True berries, such as blueberries and cranberries have seeds inside. The strawberry, however has its dry, yellow “seeds” on the outside (each of which is actually considered a separate fruit). The “seeds” seen on the outside of a strawberry are actually the plant’s ovaries and are called “achnes.”

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There are two types of squamous epithelium— simple squamous epithelium and stratified squamous epithelium. Simple squamous epithelium lines the blood vessels or alveoli in lungs. where transportation of substances occurs through selectively permeable membrane. It is made up of extremely thin and simple flat cells that form a delicate lining.