Biology MCQs

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Cloves are native to the Maluku Islands (or Moluccas) in Indonesia. They are the aromatic flower buds of a tree in the family Myrtaceae, Syzygium aromaticum. They are generally used as a spice.

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Lactic Acid is a common end product of Anaerobic Respiration. Anaerobic respiration is the type of respiration through which cells can breakdown sugars to generate energy in the absence of oxygen.

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Each adrenal gland is located on the top of each kidney (forming a hat-like structure on the top of the kidneys). Each adrenal gland has two parts viz. outer cortical portion and inner adrenal cortex. Further, there is a central part called adrenal medulla.

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Thrombocytes which are also called as platelets are a component of blood whose function is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot.

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Viruses are small infectious agents that can replicate only inside the living cells of an organism. Viruses are classified based on the type of genetic material they contain. Some viruses have DNA as their genetic material, while others have RNA. Some viruses have both DNA and RNA as their genetic material.

DNA viruses have double-stranded DNA as their genetic material. They replicate their DNA using the enzymes and machinery of the host cell. Examples of DNA viruses include herpes viruses, pox viruses, and adenoviruses.

RNA viruses have single-stranded RNA as their genetic material. They replicate their RNA using the enzymes and machinery of the host cell. Examples of RNA viruses include influenza viruses, HIV, and coronaviruses.

Viruses that have both DNA and RNA as their genetic material are known as “retroviruses.” These viruses contain a single strand of RNA, but they use an enzyme called reverse transcriptase to convert their RNA into DNA. The DNA is then integrated into the host cell’s genome and replicated along with the host cell’s DNA. Examples of retroviruses include HIV and the human T-cell leukemia virus.

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A pigment called luciferin is found in firefly. Luciferin is a light-emitting compound which is found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalyzed reaction with molecular oxygen.

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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.

Notes:
When we respire, most of the carbon dioxide as bicarbonate ions is transported in the blood. The carbon dioxide dissolved in the blood reacts with water and by the help of zinc containing enzyme called carbonic anhydrase, they form carbonic acid. It immediately dissociates to give H+ and bicarbonate ions once carbonic acid is formed. The haemoglobin present in the erythrocytes (RBCs) combines with the H+ ions immediately. The bicarbonate ion goes into the blood plasma which creates an ionic imbalance between the plasma and the erythrocytes. The chloride ions then diffuse from the blood plasma into the RBCs to maintain the ionic balance. The process of chloride ion diffusing into the erythrocytes to maintain the ionic balance is described as Hamburger’s Phenomenon.

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Euthenics is the branch of biology that studies the improvement of human race by improving environment. Eugenics is the branch of biology that studies the Improvement of human race through laws of heredity. Euphenics is the branch of biology that studies the improvement of human race by drug treatment or genetic engineering. Etiology is the branch of biology that studies the Life cycle of causal organisms of the disease.

Notes:
Liver produces a digestive fluid known as bile. Liver release bile into Gall bladder, a small, pear shaped organ located just below your liver in the upper right side of your abdomen.