Biology MCQs

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Aerobic digestion of sewage is used to produce biofuels. The fuel obtained from biomass is called biofuel.

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The renewable energy source produced by the breakdown of organic matter by some bacteria under anaerobic conditions is called Biogas. This is a mixture of methane, hydrogen, and carbon dioxide.

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Gastric acid, also known as gastric juice or stomach acid, is a digestive fluid, formed in the stomach. It is composed of hydrochloric acid (HCl), potassium chloride (KCl) and sodium chloride (NaCl). It is strongly acidic with pH varying from 1.5 to 3.5. the acid plays a key role in digestion of proteins.

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Plant morphology or phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level. It is useful in the visual identification of plants.

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Bacteria are the most abundant organisms which play important role in the decomposition of organic matter. Majority of bacteria involved in decomposition of organic matter are heterotrophs and autotrophs are least in proportion which are not directly involved in organic matter decomposition.

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Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. This disease is the most severe form of chronic Cd poisoning caused by prolonged oral Cd ingestion. It developed in numerous inhabitants of the Jinzu River basin in Toyama Prefecture, Japan, an area most severely polluted by Cd that originated from a zinc mine located upstream.

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Pulses are example of dicots since they have two cotyledons (dicot is short for ‘dicotyledon’, and ‘di’ means two). They contain two seeds inside the seed coat. Legumes (a family of plants that includes pluses, beans, peas and lentils) are all examples of dicot seeds.

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The excretory system is responsible for removing nitrogen-containing wastes from the body. The main parts of the excretory system are the kidneys. The other functions of Kidney are:
• Regulate electrolyte (salt) concentrations,
• Regulate amount of fluid within the body,
• Help regulate blood pressure,
• Help maintain acid-base balance,
• Produce hormones that affect blood and bones.

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The presence of air bubble in blood, known as air embolism, occludes blood vessels. The flow of blood is obstructed causing strokes, heart attacks, pulmonary complications. An arterial air embolism is far more dangerous than a venous embolism since it prevents oxygenated blood from reaching the target organ and cause ischemia. It can even lead to heart attack or stroke leading to death.

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Drones are male honey bees. They develop from eggs that have not been fertilized, and they cannot sting, since the worker bee’s stinger is a modified ovipositor (an egg laying organ). Drones die soon after mating with female partner.