Biology MCQs

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Heart disease and High blood pressure are examples of Multifactorial Genetic Inheritance. It is also known as polygenic inheritance.

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Bacteria protect themselves from viruses by fragmenting viral DNA with Exonuclease. Enzymes that work by cleaving one nucleotide at a time from the end (Exo) of the polynucleotide chain are called exonucleases.

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Traditional biotechnology and Modern molecular biotechnology are two ideas included in the definition of biotechnology.

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Hydra is radially symmetrical, that is, the parts of its body are arranged in a circle around a central median axis passing through the mouth. Hydra reproduces by asexual and sexual methods. Asexual reproduction takes place either by budding or by fission.

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Stomata are tiny openings or pores in plant tissue that allow for gas exchange. Stomata allow a plant to take in carbon dioxide, which is needed for photosynthesis. They also help to reduce water loss by closing when conditions are hot or dry. Stomata look like tiny mouths which open and close as they assist in transpiration.

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The phosphate groups on DNA are ionic and charged. Each phosphate group on the DNA backbone has one unit of negative charge (-1). Charged molecules attract water and are hydrophilic. DNA has two hydrophilic polar external backbones made of sugars and phosphate groups joined by ester bonds. Therefore, DNA as nucleic acid is characterized by presence of phosphodiester bond.

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The bark of the common Willow tree is the source of a wide range of phenolic glycosides, of which the most important is salicin. Salicin is metabolized into salicylic acid in the human body, and is a precursor of aspirin. It is used as a fever reducer, a mild pain reliever, and an anti-inflammatory.

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Evolutionary biologists now classify wisdom teeth as vestigial organs, or body parts that have become functionless due to evolution. They believe wisdom teeth, or the third set of molars, were the evolutionary answer to our ancestor’s early diet of rough food – like leaves, roots, nuts and meats – which required more chewing power and resulted in excessive wear of the teeth. The modern diet with its softer foods has made the need for wisdom teeth nonexistent.

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Alveoli are the small balloon-like sacks of 200– 500 ?m diameter, making up a vital part of the respiratory zone of the lungs. Each alveolus (singular) plays an important role in letting oxygen and carbon dioxide move into and from the blood stream during inhalation and exhalation. he balloon-shaped alveoli cover approximately 70 square meter area within the lungs, with this wide surface area contributing towards a more efficient gas exchange.

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Lactobacillus acidiphilous is used in milk curdling by producing lactic acid and reducing the pH of the milk. These bacteria convert the lactose into lactic acid, which imparts the sour taste to curd. It is a genus of Gram positive facultative anaerobic or microaerophilic rod-shaped bacteria.