Advanced Biotech Miscellaneous


Advanced Biotech Miscellaneous

  1. Baculovirus expression system is used to express heterologous genes in









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    Baculovirus expression in insect cells represents a robust method for producing recombinant glycoproteins. Baculovirus-produced proteins are currently under study as therapeutic cancer vaccines with several immunologic advantages over proteins derived from mammalian sources. ​

    Correct Option: C

    Baculovirus expression in insect cells represents a robust method for producing recombinant glycoproteins. Baculovirus-produced proteins are currently under study as therapeutic cancer vaccines with several immunologic advantages over proteins derived from mammalian sources. ​


  1. Restriction endonucleases from two different organisms that recognize the same DNA sequence for cleavage are called ​









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    Isoschizomers are pairs of restriction enzymes specific to the same recognition sequence. For example, Sph I (CGTAC/G) and Bbu I (CGTAC/G) are isoschizomers of each other. The first enzyme to recognize and cut a given sequence is known as the prototype, all subsequent enzymes that recognize and cut that sequence are isoschizomers. Isoschizomers are isolated from different strains of bacteria and therefore may require different reaction conditions. ​

    Correct Option: A

    Isoschizomers are pairs of restriction enzymes specific to the same recognition sequence. For example, Sph I (CGTAC/G) and Bbu I (CGTAC/G) are isoschizomers of each other. The first enzyme to recognize and cut a given sequence is known as the prototype, all subsequent enzymes that recognize and cut that sequence are isoschizomers. Isoschizomers are isolated from different strains of bacteria and therefore may require different reaction conditions. ​



  1. To produce plants that are homozygous for all traits, the best choice is ​​









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    In anther culture, the anther swells and dehisces along its upper margin, lengthwise. This phenomenon helps to expose the pollen grain. Alternatively, huge amount of pollen grains can be isolated manually and can be cultured aseptically very easily. Therefore, pollen is more suitable material than egg cell for the production of haploid. The development and production of haploid plant in vitro is very important for the study of fundamental and applied aspects of genetics in the higher plants. Production of homozygous diploid by doubling the chromosome number of haploid in vitro makes a pure line in single step and such homozygous pure line is of great importance in plant breeding. Also it is easy to induce cell division in immature pollen cells in some species. By anther and pollen culture, haploids can be produced in large numbers very quickly. ​

    Correct Option: C

    In anther culture, the anther swells and dehisces along its upper margin, lengthwise. This phenomenon helps to expose the pollen grain. Alternatively, huge amount of pollen grains can be isolated manually and can be cultured aseptically very easily. Therefore, pollen is more suitable material than egg cell for the production of haploid. The development and production of haploid plant in vitro is very important for the study of fundamental and applied aspects of genetics in the higher plants. Production of homozygous diploid by doubling the chromosome number of haploid in vitro makes a pure line in single step and such homozygous pure line is of great importance in plant breeding. Also it is easy to induce cell division in immature pollen cells in some species. By anther and pollen culture, haploids can be produced in large numbers very quickly. ​


  1. Match Group I with Group II
    ​​
    Group–I​  ​ Group–II
    P.​ Real Time-PCR​ 1. ​Biochips
    ​​​​Q.​ 2-D Electrophoresis​ 2.​ Syber Green
    R.​ Affinity ​ 3.​ Antibody linked ​​​chromatography​​sephrose beads​
    ​​S.​ Micoroarray​ ​​ 4.​ Ampholytes ​ ​











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    Real time quantitative PCR allows the sensitive, specific and reproducible quantification of nucleic acids. Real time PCR allows precise quantification of specific nucleic acids in a complex mixture even if the starting amount of the material is at a very low concentration. This is accompanied by monitoring the amplification of a target sequence in real time using fluorescent technology. A common approach uses SYBR GREEN I. It binds to any double stranded DNA which could result in inaccurate data. ​​
    2-D electrophoresis is used to separate and display all gene products present. This technique technique separate proteins in two steps according to two independent properties: the first-dimension is isoelectric focussing (IEF), which separated proteins according to their more isoelectric points (pI); the second dimension is SDS-polyacrylamide gel electrophoresis (SDS-PAGE) which separates protein according to their molecular weights (MW). The procedure involves placing the sample in gel with a pH gradient and applying a potential difference across it. There are two alternative methods to create pH gradient → carries ampholytes and immobilized pH gradient (IPG) gels.
    ​​Affinity chromatography is a powerful tool for the purification of specific biomolecules, including proteins. The basic principle is that a biospecific ligand is immobilized to a solid support or resin to which a solution containing the protein of interest is passed over. Ligands are often based on biological functional pairs, such as enzymes and substrates or antigens and antibodies. The specific ligand binds the protein of interest and all non-specific molecules are washed away. The protein is eluted in a specific buffer, either by pH or ionic strength shift or by competitively displacement elution. Examples of resin are → CNBr-agarose, antibody linked sepharose beads, etc. ​​
    Microarray is a multiplex lob on a chip. It is 2-D array on a solid substrate (usually a glass slide or silicon thin-film cell) that assays large amounts of biological material using high-throughput screening methods. Types of microarray include DNA microarrays (biochips are used), Protein microarrays, etc.

    Correct Option: C

    Real time quantitative PCR allows the sensitive, specific and reproducible quantification of nucleic acids. Real time PCR allows precise quantification of specific nucleic acids in a complex mixture even if the starting amount of the material is at a very low concentration. This is accompanied by monitoring the amplification of a target sequence in real time using fluorescent technology. A common approach uses SYBR GREEN I. It binds to any double stranded DNA which could result in inaccurate data. ​​
    2-D electrophoresis is used to separate and display all gene products present. This technique technique separate proteins in two steps according to two independent properties: the first-dimension is isoelectric focussing (IEF), which separated proteins according to their more isoelectric points (pI); the second dimension is SDS-polyacrylamide gel electrophoresis (SDS-PAGE) which separates protein according to their molecular weights (MW). The procedure involves placing the sample in gel with a pH gradient and applying a potential difference across it. There are two alternative methods to create pH gradient → carries ampholytes and immobilized pH gradient (IPG) gels.
    ​​Affinity chromatography is a powerful tool for the purification of specific biomolecules, including proteins. The basic principle is that a biospecific ligand is immobilized to a solid support or resin to which a solution containing the protein of interest is passed over. Ligands are often based on biological functional pairs, such as enzymes and substrates or antigens and antibodies. The specific ligand binds the protein of interest and all non-specific molecules are washed away. The protein is eluted in a specific buffer, either by pH or ionic strength shift or by competitively displacement elution. Examples of resin are → CNBr-agarose, antibody linked sepharose beads, etc. ​​
    Microarray is a multiplex lob on a chip. It is 2-D array on a solid substrate (usually a glass slide or silicon thin-film cell) that assays large amounts of biological material using high-throughput screening methods. Types of microarray include DNA microarrays (biochips are used), Protein microarrays, etc.



  1. A cell has five molecules of a rare mRNA. Each cell contains 4 × 105 mRNA molecules. How many clones one will need to screen to have 99% probability of finding at least one recombinant cDNA of the rare mRNA, after making cDNA library from such cell? ​









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    Number of clones which have 99% probability = log10 (1– 0.99) / log10 (1– 5 / 4 * 105) = log10 (0.01) / log10 (0.9999875)
    = (– 4.605) / (–1.25) * 10–5 = 3.5 * 10–5

    Correct Option: B

    Number of clones which have 99% probability = log10 (1– 0.99) / log10 (1– 5 / 4 * 105) = log10 (0.01) / log10 (0.9999875)
    = (– 4.605) / (–1.25) * 10–5 = 3.5 * 10–5