Biology MCQs

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A kidney transplant is the best long-term solution for kidney failure. Complete failure of the kidneys allows urea and other waste products to build up in the blood.

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Herbert W. Boyer and Stanley N proposed rDNA technology. Recombinant DNA (rDNA) is a technology that uses enzymes to cut and paste together DNA sequences of interest.

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The brain’s limbic system controls emotional expression through the hypothalamus, which has control over the body’s emotional responses systems. The hypothalamus is responsible for regulating hunger, thirst, response to pain, levels of pleasure, sexual satisfaction, anger and aggressive behavior, etc. It also regulates pulse, blood pressure, breathing, and arousal in response to emotional circumstances.

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The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the opening. Guard cells are specialized cells in the epidermis of leaves, stems and other organs that are used to control gaseous exchange and rate of transpiration.

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Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest. Pesticides are a special kind of products for crop protection. A pesticide is generally a chemical or biological agent (such as a virus, bacterium, antimicrobial or disinfectant) that through its effect deters, incapacitates, kills or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, spread disease or are vectors for disease.

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When cells are exposed to sunlight, radiant energy can damage the DNA. For example, ultraviolet irradiation causes covalent bond formation between adjacent thymines on the same strand of DNA.

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2, 4-Dichlorophenoxyacetic acid is a s a wide range selective weedicide which controls broad leaf type (DICOT) weeds in paddy fields, tea plantations, sugarcane fields, fruit orchards etc. It is one of the most widely used herbicides in the world.

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Tears are a clear liquid secreted by the lacrimal glands (tear ducts) in the eyes of all land mammals. The lacrimal glands are situated in the upper lateral region of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone. They are paired, almond-shaped exocrine glands, one for each eye.

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Quenching is a process in which absorbed light energy is dissipated as heat and does not take part in photochemistry. The phenomenon involves quenching of chlorophyll a fluorescence, which is induced under steady-state illumination.

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Endemic plants and animals are those that are unique to a specific geographic region. This makes them incredibly special and more vulnerable to extinction. Because they are only found in certain locations, they require special conservation efforts. Koalas, kangaroos, and emperor penguins are all endemic to Hawaii, Australia, and Antarctica.