多选题 3.00分

共用题干 第一篇Genetic EngineeringGenetic engineering began when the DNA molecule(分子),the most basic unit o...

共用题干
第一篇

Genetic Engineering

Genetic engineering began when the DNA molecule(分子),the most basic unit of life , was first
described in 1953 by James Watson and Francis Crick.An understanding of DNA led to the altering of
normal cell reproduction.Experiments with altering human cells began in 1970.In one of the first
experiments,patients were injected with a virus that would produce a life-saving enzyme,but their bodies
would not accept it.In 1980 patients with a rare but fatal blood disease were injected with a purified gene
that was cloned through DNA technology.Another failure.
Genetic engineering got a legal boost(激励)in 1980. The U. S. Supreme Court said that a patent could
be granted on a genetically engineered "oil-eating" bacterium(细菌).This bacterium would help clean up
oil spills.The ruling encouraged companies to invent new life forms,and three important medical products
were quickly developed.bacterium produced human interferon as a by-product. This new product reduced the cost of interferon.expensive growth hormone was previously produced from human cadavers,but by changing the genetic make-
up of the single-cell bacterium E.coli,and affordable growth hormone could be produced.or-pork-based product until 1982.Now insulin can be manufactured by genetically altered bacteria.
Advances in genetic engineering have continued,though they constantly must be weighed against the
safety of procedures.There is clearly much more to discover. This passage is mainly about_________.
  • A.the effects of altering cells
  • B.the human growth hormone
  • C.insulin resistance
  • D.U.S.Supreme Court rulings

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