Pesticide resistant rape plants
Scientists have transferred a gene to the rape plant which
enables the plant to resist a certain pesticide. When the
farmer sprays his genetically modified rape crop with pesticides,
he or she can destroy most of the pests without killing the
- The farmer can grow a larger crop because it is easier
to fight pests.
- In some cases the farmer can use a more environmentally
friendly crop spray.
- The farmer can also protect the environment by using less
- Genes from the genetically modified rape crop could be
transferred to the pests. The pests then become resistant
to the crop spray and the crop spraying becomes useless.
- Rape plants can pollinate weeds - for example navew which
is found in rape fields. When rape plants pollinate the
navew their genes are transferred. The navew then acquires
Corn, soya beans and sugar cane have also
been genetically modified by scientists so they are able to
tolerate crop spray.
Insecticide sweet corn
Scientists have genetically modified sweet corn so that
it produces a poison which kills harmful insects. This
means the farmer no longer needs to fight insects with
insecticides. The genetically modified corn is called
Bt-corn, because the insect-killing gene in the plant
comes from the bacteria Bacillus thuringiensis.
- The farmer no longer has to use insecticide to kill insects,
so the surrounding environment is no longer exposed to large
amounts of harmful insecticide.
- The farmer no longer needs to walk around with a drum
of toxic spray wearing a mask and protective clothing.
- This type of genetically modified corn will poison the
insects over a longer period than the farmer who would spray
the crops once or twice. In this way the insects can become
accustomed (or resistant) to the poison. If that happens
both crop spraying and the use of genetically modified Bt-corn
- A variety of insects are at risk of being killed. It might
be predatory insects that eat the harmful ones or, perhaps
attractive insects such as butterflies. In the USA, where
Bt-corn is used a great deal there is much debate over the
harmful effects of Bt-corn on the beautiful Monarch butterfly.
Cotton and potatoes are other examples of plants that scientists
have , genetically modified to produce insecticide.
Golden rice is genetically modified rice that now contains
a large amount of A-vitamins. Or more correctly, the rice
contains the element beta-carotene which is converted in the
body into Vitamin-A. So when you eat golden rice, you get
more vitamin A.
Beta-carotene gives carrots their orange
colour and is the reason why genetically modified rice
is golden. For the golden rice to make beta-carotene
three new genes are implanted: two from daffodils and
the third from a bacterium.
- The rice can be considered a particular advantage to
poor people in underdeveloped countries. They eat only an
extremely limited diet lacking in the essential bodily vitamins.
The consequences of this restricted diet causes many people
to die or become blind. This is particularly true in areas
of Asia, where most of the population live on rice from
morning to evening.
- Critics fear that poor people in underdeveloped countries
are becoming too dependent on the rich western world. Usually,
it is the large private companies in the West that have
the means to develop genetically modified plants. By making
the plants sterile these large companies can prevent farmers
from growing plant-seed for the following year - forcing
them to buy new rice from the companies.
- Some opposers of genetic modification see the "golden
rice" as a method of making genetic engineering more
widely accepted. Opponents fear that companies will go on
to develop other genetically modified plants from which
they can make a profit. A situation could develop where
the large companies own the rights to all the good crops.
Long-lasting, genetically modified tomatoes came on to the
market in 1994 and were the first genetically modified food
available to consumers. The genetically modified tomato produces
less of the substance that causes tomatoes to rot, so remains
firm and fresh for a long time.
- Because the GM tomatoes can remain
fresh longer they can be allowed to ripen in the sun
before picking - resulting in a better tasting tomato.
- GM tomatoes can tolerate a lengthier
transport time. This means that market gardens can
avoid picking tomatoes while they are green in order
that they will tolerate the transport.
- The producers also have the advantage
that all the tomatoes can be harvested simultaneously.
- Scientists today can genetically modify tomatoes without
inserting genes for antibiotic resistance. However the first
genetically modified tomatoes contained genes that made
them resistant to antibiotics. Doctors and vets use antibiotics
to fight infections. These genes spread to animals and people,
doctors would have difficulties fighting infectious diseases.
Strawberries, pineapples, sweet peppers and bananas have
all been genetically modified by scientists to remain fresh