Genetic engineering
is a laboratory technique used by scientists to
change the DNA of living organisms.
DNA is the blueprint for the individuality
of an organism. The organism relies upon the
information stored in its DNA for the management
of every biochemical process. The life, growth
and unique features of the organism depend on
its DNA. The segments of DNA which have been
associated with specific features or functions
of an organism are called genes.
Molecular biologists have discovered many enzymes
which change the structure of DNA in living
organisms. Some of these enzymes can cut and
join strands of DNA. Using such enzymes, scientists
learned to cut specific genes from DNA and to
build customized DNA using these genes. They
also learned about vectors, strands of DNA such
as viruses, which can infect a cell and insert
themselves into its DNA.
With this knowledge, scientists started to
build vectors which incorporated genes of their
choosing and used the new vectors to insert
these genes into the DNA of living organisms.
Genetic engineers believe they can improve the
foods we eat by doing this. For example, tomatoes
are sensitive to frost. This shortens their
growing season. Fish, on the other hand, survive
in very cold water. Scientists identified a
particular gene which enables a flounder to
resist cold and used the technology of genetic
engineering to insert this 'anti-freeze' gene
into a tomato. This makes it possible to extend
the growing season of the tomato.
