Traditionally,in plant breeding,there are crossing varieties of the same species in ways they could cross naturally.For example,disease-resistant varieties of wheat have been
crossed with highyield wheat to combine these properties.This type of natural gene exchange is safe and fairly predictable.
Genetic engineering(GE)makes it possible to exchange genes between unrelated species that cannot exchange genes with each other in a natural way.GE can involve the
exchange of genes be-tween vastly different species一e.g. putting scorpion toxin genes into maize or fish antifreeze genes into tomatoes.It is possible that a scorpion toxin
gene,even when it is in maize DNA,will still get the organism to produce scorpion toxin一but what other effects may it have in this alien environment? We have already
realized this problem一adding human growth hormone genes to pigs certainly makes them grow一but it also gives them arthritis and makes them cross-eyed,which was
entirely out of expectation.
It won't be difficult to find out,for example,that the gene for human intelligence will not have the same effect if it is inserted into cabbage DNA as it had in human DNA一but
what side-effect would it have?In other words,is genetically modified(GM)food safe to eat?The answer is that no-body knows because long-term tests have not been carried
out.
Those companies who want a GM product approved in the
were apparently fed to fish for 10 weeks before being approved.There was no requirement for independent testing,for longterm testing,for testing on humans or testing for
specific dangers to children or allergic people.
The present opinion of the British Government is that"There is no evidence of long-term dangers from GM foods."In the
now being prosecuted for covering up research that suggested possible risks from GM foods.Which statementabout GM product is true according to the passage?
A.Adding humangrowth hormone genes to pigs does not make them grow.
B.The American Foodand Drug Administration is now doing a research that suggested possible risksfrom GM foods.
C.The gene for humanintelligence will not have the same effect if it is inserted into cabbage DNAas it had in human DN
D. There has beenrequirement for independent testing,for long-term testing,for testing on humansor testing for specific dangers to children or allergic people.