Biology MCQs

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Pearls are composed primarily of calcium carbonate, which is what gives them their unique luster. They are formed within the shell of certain mollusks as a defense mechanism against a potentially threatening irritant, such as a parasite. Over time, the mollusk continually deposits layers of calcium carbonate, which eventually forms a smooth, hard pearl. This process can take up to eight years.

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The radiations used in Radiotherapy for the treatment of Cancer destroys the Cancer tumour mainly by Destroying the DNA of the Cancerous Cells. It uses high doses of radiation to kill cancer cells and shrink tumors.

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In biology, a taxon (plural taxa; back-formation from taxonomy) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit.

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Ophiology is the branch of Biology that study Snakes. Thus Option [B] is correct. While the study of Moths and Butterflies is called as Lepidoteriology, The study of whale is called as Cetology and the study of Ants is called as Myrmecology.

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Drugs that bind to receptor sites and inhibit their natural function are called antagonists. These drugs are useful when a message needs to be blocked.
Antagonists bind to receptors but do not activate them. They compete with available agonists for receptor binding sites. Antagonists block the access or attachment of the body’s natural agonists, usually neurotransmitters, to their receptors. This prevents or reduces cell responses to natural agonists.
Antagonists still cause a response, but this is through blocking the actions of agonists.
Agonist and antagonist drugs can be used together in people with asthma. For example, albuterol can be used with ipratropium.

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The connective tissues include several types of fibrous tissue that vary only in their density and cellularity, as well as the more specialized and recognizable variants—bone, ligaments, tendons, cartilage, and adipose tissue. Skin is not a connective tissue. It is the body’s largest organ and consists of multiple layers, including the epidermis (outermost layer) and the dermis (deeper layer). Skin primarily serves as a protective barrier and regulates temperature, but it is mainly classified as an epithelial tissue due to its structure and function.

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Causes range from bacteria, viruses, and parasites to food reactions and unclean water. The flu comes with symptoms like fever, congestion, muscle aches, and fatigue. The cause is the influenza virus. More severe cases can lead to life-threatening illnesses like pneumonia.

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Ribosome and Endoplasmic reticulum are main site for protein synthesis. Ribosome, which serve as staging area where some RNA helps in protein synthesis. Endoplasmic reticulum is an irregular, double membrane network scattered in cytoplasm, also helps in protein synthesis.

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Sericulture – It refers to the rearing of silk worms and obtaining silk from them. It involves raising a feed crop, chiefly mulberry leaves, and tending to silk worms and obtaining silk fibre from the cocoons produced by the worms.
Varieties – There are a number of varieties of worm reared for silk production, the most important variety being Bombyx mori.

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The process of oxidation of oily and Fatty food, which changes its taste and smell is known as Rancidity. Rancidity generally occurs in Fat.