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I am Hassam ur Rahman and I am teaching Fsc biology since 2014 .I am always trying to improve myself and provide best lecture to students.i am taking content for the lecture from authentic and relevant sources but human errors are possible . you are requested to please highlight the mistakes.My lectures are equally reliable for Fsc and mdcat students
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This lecture is about
Transgenic Plants

Techniques have been developed to introduce foreign genes into immature plant
embryos, or into plant cells that have had the cell wall removed and are called
protoplasts. It is possible to treat protoplasts with an electric current while they are
suspended in a liquid containing foreign DNA. The electric current makes tiny, selfscaling
holes in the plasma membrane through which genetic material can enter. Then a
protoplast will develop into a complete plant. Foreign genes transferred to cotton, com
and potato strains have made these plants resistant to pests because their cells now
produce an insect’toxin. Similarly, soybeans have been made resistant to a common
herbicide. Some corn and cotton plants are both pest and herbicide resistant. In 1999
these transgenic crops were planted on more than 70 million acres worldwide and the
acreage is expected to triple in about five years. Improvements still to come for are
increased protein or starch content and modified oil or amino acid composition.
Agribusiness companies also are in the process of developing transgenic versions
of wheat and rice in addition to com. This is considered an absolute necessity if the
2020 global demand for rice, wheat and com is to be met. World grain harvests have
continued to rise since the 1960s when special high-yield hybrid plants were developed
during the so called green revolution. But the per capita production has now flattened
out because of continued population growth. The hope is that genetic engineering will
allow fanners to surpass the yield barrier. Perhaps, the stomata, the pore-like openings
in the leaves, could be altered to boost carbon dioxide intake or cut down water loss.
Another possible goal is to increase the efficiency of the enzyme Rubisco which captures
C02 in most plants. A team of Japanese scientists are attempting to introduce the C4
cycle into the rice. Plants that utilize the C4 cycle avoid the inefficiency of carboxylase
by using a different means of capturing C02. Unlike the single gene transfers that have
been done so far, these modifications would require a thorough re-engineering of
plant cells. Single gene transfers will cause plants to produce various products. A weed
called mouse-eared cress has been engineered to produce a biodegradable plastic
(polyhydroxy-butyrate) in cell granules.
Plants are being engineered to produce human hormones, clotting factors, and
antibodies in their seeds. One type of antibody made by com can deliver radio
isotopes to tumor cells, and another made by soybeans can be used as treatment for
genital herpes. Plant-made antibodies are inexpensive and there is little worry about
contamination with pathogens that could infect people. Clinical trials have begun.

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