Biology MCQs

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A gene is a functional unit of chromosomes. They are made up of DNA. Some genes also act as instructions to make molecules called proteins. However, not all genes code for proteins.

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Down’s syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21.Down’s syndrome is the most common chromosome abnormality in humans. It is typically associated with a delay in cognitive ability (mental retardation, or MR) and physical growth, and a particular set of facial characteristics

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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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The Red color of Red wine is mainly because of pigments such as anthocyanin. Anthocyanin is present in many fruits like plums, blueberries, and cherries.

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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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A single gene may have two or more phenotypic expressions or characters. The multiple phenotypic effect of a single gene is called pleiotropism. Hence the gene associated with this phenomenon is called Pleiotropic gene.

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Edaphology is one of the two branches of soil sciences which deals with the scientific study of influence of soils on the vegetative matter such as plants.

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The main criteria of the five kingdom classification were cell structure, body organisation, mode of nutrition and reproduction, and phylogenetic relationships.

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Hemoglobin has a quaternary structure. It consists of two pairs of separate proteins, designated α and β chains.

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Hepadnavirus B (hepatitis B virus, HBV) belongs to the genus Orthohepadnavirus of the Hepadnaviridae family. It is an important cause of viral hepatitis in humans worldwide.