GENETICS OF THE FUTURE:sslc biology notes

Biotechnology is the use of microrganisms and
biological processes for various human requisites.
Traditionally man adopted and practiced this;
• Yeast (a fungus) was used to prepare food items like
• Bacteria and fungi were utilized to convert sugar in to
alcohol to make wine, appam or cake.
Genetic engineering or gene technology is the modern
form of biotechnology.
Genetic engineering is a technology that controls
traits of organisms by bringing about desirable
changes in their genetic constitution.
This technology becomes beneficial to mankind in the
following ways:

  • Genetically modified organisms that produce medicines,
    food items and other products.
  • High productive and disease resistant varieties.
  • Remedy of genetic diseases through Gene therapy
  • DNA finger printing/profiling to identify real person.
    Genetic modification in organism is done by cutting
    or joining specific genes, using certain enzymes.
    Eg:- the stages in the production of human insulin
    bacteria through the process of genetic engineering, are:
    a- From human DNA, cut the gene responsible for the
    production of insulin.
    b- Plasmid (circular DNA) is isolated from a
    c- Human insulin gene is ligated with the isolated
    plasmid, which is used as the ‘vector’.
    d- Insert this ligated plasmid in to another bacterial
    e- This bacterium is allowed to multiply in a culture
    medium to produce inactive insulin.
    f- Active insulin is produced from this.
    The enzymes like Restriction endonuclease, used to
    cut DNA at specific sites, are generally called as
    ‘genetic scissors’. The enzymes like Ligase, used for
    joining DNA at specific sites, are generally called
    as ‘genetic glue’.
    The Human Genome Project
    The sum of genetic material present in an organism
    is called its genome. The human genome has 24000
    functional genes present in the 46 chromosomes.
    [Majority of our genes seen in the chromosomes are
    non functional and is known as ‘junk genes’]To find out the exact gene for a
    specific trait and its location in our
    genome, a project called Human
    Genome Project, started in 1990
    and ended in 2003 in various
    laboratories of the world.
    The Gene mapping is the technology helped us to
    identify the location of a gene in the DNA.
    Gene mapping is a technology by which we can
    locate a specific gene in the DNA responsible for a
    particular trait.
    Gene therapy is a method of treatment in which the
    genes that are responsible for diseases are removed
    and normal functional genes are inserted in their place.
    Gene therapy has triggered great hope in the
    control of genetic diseases.
    ‘Pharm animals’ are genetically modified animals
    which provide pharmaceuticals or medicines. Genes
    responsible for the production of human insulin and
    growth hormones etc. are identified and inserted in
    animals like cow or pig to transform them in to
    ‘pharm animals’.
    Examples for proteins, used as medicines :
    Interferons (for viral disease),
    Endorphin (for pain relief),
    Somatotropin (for growth disorders),
    Insulin (for diabetes mellitus).
    DNA profiling
    The technology of testing the arrangement of
    nucleotides in the DNA of persons is called DNA
    profiling or DNA finger printing (DNA testing).
    Alec Jeffrey proposed this because the arrangement of
    nucleotides in the DNA of each person differs.
    The scope of DNA testing:
  • To find out hereditary characteristics,
  • To identify real parents in the case of parental dispute
  • To identify persons found after a long periods of
    missing due to war or natural calamities.
  • To prove murder, robbery etc.
    Possibilities to misuse genetic engineering:
    It is criticized that genetically modified varieties
    are threat to indigenous varieties and may cause health
    issues to human. There are possibilities to use the
    genetically modified organisms as ‘bio-weapons’.
    However, science and technologies are meant for
    protection, not for destruction.
    You-tube link of focus area covered portion of this chapter :

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