Biology MCQs

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The cork cells are impervious to water. Suberin is responsible to give this quality to Cork. Suberin, cutin and lignins are complex, higher plant epidermis and periderm cell-wall macromolecules, forming a protective barrier.

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Myosins refers to a superfamily of motor proteins known for their roles in muscle contraction and other motility processes in eukaryotes. These proteins are basically specialized motor machines that convert the cellular free energy to mechanical work. They depend on ATPs for actin based motility.

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Vitamin E is called ant sterility vitamin. Vitamin E, a fat soluble vitamin, is found naturally in some foods, added to others, and available as a dietary supplement.

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RSV Virus (respiratory syncytial virus) is also called as “Hit & Hide” virus. It causes infections of the lungs and respiratory tract. It is a major cause of lower respiratory tract infections.

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Anesthesia which allows patients to undergo surgery without the distress and pain they would otherwise experience, has been practiced by man since ancient times. Opium (poppy) is the most ancient source of anesthesia preparations.

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For reasons of safe transportation of fruits, mangoes, bananas etc are picked before they ripen fully. Slightly green harvested mangoes are subjected to small containers of calcium carbide (CaC2) with a plastic covering. CaC2 reacts with the moisture in the air to release acetylene (or ethyne) gas as follows:
CaC2 + 2 H2O – C2H2 + Ca(OH)2
This option may give you slightest confusion if you don’t know the difference between Ethylene and Ethyne (Acetylene). Both are chemical substances produced by fruits to accelerate the normal process of fruit maturation — is a ripening hormone. Ethylene is C2H4 and has a carbon-carbon double bond. Acetylene is C2H2 and has a carbon-carbon triple bind. Acetylene contains more energy and burns hotter than ethylene. Ethylene is a gaseous compound , Acetylene is the chemical compound , which is the simplest alkyne and is also a hydrocarbon while Ethylene is the simplest alkene and classified as an unsaturated hydrocarbon. I hope you will never forget it now.

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The human body needs red blood cells and platelets to remain healthy. But in Leukemia increased white blood cells crowd out the red blood cells and platelets. Leukemia is a blood cancer caused by a rise in the number of white blood cells in your body.

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The Peepal tree uses Crassulacean Acid Metabolism (CAM) photosynthesis, allowing CO₂ uptake at night and oxygen release, a trait seen in some succulents and epiphytes to minimize water loss. CAM enables the Peepal to continue gas exchange during the night, unlike typical C3 or C4 plants.

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The most primitive life forms on Earth are prokaryotes, which are the simplest cellular forms of life. Prokaryotes include archaea and bacteria, which have been found on Earth for 3.5 to 3.8 billion years.
The earliest known life forms on Earth are fossilized microorganisms found in hydrothermal vent precipitates. These microorganisms are believed to be about 3.42 billion years old.
The first life forms were probably a tiny bacteria called archaebacteria. These bacteria thrive in very hot, chemically rich places.

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Xerophytes can tolerate and stand against drought conditions. They are able to survive in an environment with little liquid water, such as a desert or an ice- or snow-covered region in the Alps or the Arctic.