Biology miscellaneous


  1. The metal ion present in vitamin B12 is :









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    The structure of B12 is based on a corrin ring, which is similar to the porphyrin ring found in heme, chlorophyll, and cytochrome. It contains the biochemically rare element cobalt sitting in the center of the ring. Also called cobalamin, it is a water-soluble vitamin.

    Correct Option: A

    The structure of B12 is based on a corrin ring, which is similar to the porphyrin ring found in heme, chlorophyll, and cytochrome. It contains the biochemically rare element cobalt sitting in the center of the ring. Also called cobalamin, it is a water-soluble vitamin.


  1. The gene which exhibites multiple effects is known as :









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    Pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. The underlying mechanism is that the gene codes for a product that is, for example, used by various cells, or has a signaling function on various targets. A classic example of pleiotropy is phenylketonuria, a human disease that affects multiple systems but is caused by one gene defect.

    Correct Option: B

    Pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. The underlying mechanism is that the gene codes for a product that is, for example, used by various cells, or has a signaling function on various targets. A classic example of pleiotropy is phenylketonuria, a human disease that affects multiple systems but is caused by one gene defect.



  1. Which of the following plant shows chloroplast dimorphism?









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    Certain plans which possess the C4 dicarboxylic acid pathway of CO2 fixations show a structural dimorphism of chloroplast structure. Sugarcane is a common example of C4 plant that has dimorphic chloroplast. The mesophyll cells possess chloroplasts with well developed grana whereas the bundle sheath chloroplasts lack the organization of grana (Agranal chloroplasts). The malic acid is transported to the bundle sheath chloroplast (Transportations). Here it is converted to pyruvic acid and CO2 by NADP+ malic enzyme (Decarboxylation). The pyruvic acid is then transported to mesophyll chloroplasts (Transportation).

    Correct Option: D

    Certain plans which possess the C4 dicarboxylic acid pathway of CO2 fixations show a structural dimorphism of chloroplast structure. Sugarcane is a common example of C4 plant that has dimorphic chloroplast. The mesophyll cells possess chloroplasts with well developed grana whereas the bundle sheath chloroplasts lack the organization of grana (Agranal chloroplasts). The malic acid is transported to the bundle sheath chloroplast (Transportations). Here it is converted to pyruvic acid and CO2 by NADP+ malic enzyme (Decarboxylation). The pyruvic acid is then transported to mesophyll chloroplasts (Transportation).


  1. An eazyme produced by HIV that allows the integration of HIV DNA into the host cell’s DNA is :









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    HIV’s enzyme for inserting the DNA version of its genome into the host cell DNA is called its “integrase”. HIV-1 integrase catalyzes the “cut-and-paste” action of clipping the host DNA and joining the proviral genome to the clipped ends. It is also produced by viruses containing double-stranded DNAs for the same purpose.

    Correct Option: B

    HIV’s enzyme for inserting the DNA version of its genome into the host cell DNA is called its “integrase”. HIV-1 integrase catalyzes the “cut-and-paste” action of clipping the host DNA and joining the proviral genome to the clipped ends. It is also produced by viruses containing double-stranded DNAs for the same purpose.



  1. Which among the following is thesweetest sugar?









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    There are primarily three types of sugar: glucose, fructose and sucrose. Of the three sugars, fructose is the sweetest and glucose the least sweet, so typically less fructose can be used than table sugar (sucrose) – if sucrose has a sweetness of one, fructose is 1.7 and glucose 0.74. Fructose is known as the fruit sugar as its make source in the diet is fruits and vegetables.

    Correct Option: B

    There are primarily three types of sugar: glucose, fructose and sucrose. Of the three sugars, fructose is the sweetest and glucose the least sweet, so typically less fructose can be used than table sugar (sucrose) – if sucrose has a sweetness of one, fructose is 1.7 and glucose 0.74. Fructose is known as the fruit sugar as its make source in the diet is fruits and vegetables.