The Secret of Life教案

2. does a plant have a structure?
yes, it does.
3. what are the benefits of learning english?
international communication.
4. can you think of a technology that is used in business?
computer technology.
5. which two words in the box can have more or less the same meaning?
advance, development
6. if you insert something, what do you do?
put it into something else.
step 6 find these sentences and phrases in the passage.
1. the discovery of dna has been called the most important biological work of the last 100 years. why?
  because it has such a big influence on our lives.
2. but when he committed the murder, waters left some of his own cells on his victim.
what were scientists able to do as a result?
match the dna in the cells to the dna of the suspect.
3. two months later julia had a small but very expensive operation …
what do you think the surgeon did?
4. he’s a world champion again …
  why doesn’t mark deserve to be a world champion?
because he is not a “natural” champion.
5. … hospital tests showed that her child would have this illness.
why did clara have hospital tests?
to find our if their unborn child had the family’s hereditary disease.
6. a new future is approaching.
why does the writer say this?
because genetic engineering will become very common and change everything.
7. on the other hand, we may soon be able to get rid of the disease --- but keep the baby!
how might we do this?
8. … there are many important issues to discuss.
can you give some examples?
period three
content: reading practice
step 1 answer the questions
1. what is genetically modified food?
2. how can you tell the difference between ordinary food and gm food?
3. how much gm food is there in china?
4. what are the advantages of gm food?
5. what are the disadvantages?
6. what should we do about gm food in china?
step 2 discussion
not much is known about long-term effects of gm food on humans and the environment. it is “unpredictable”.
step 3 read the text again and answer the following questions
1. is transgenic food the same as genetically modified food?
    yes.
2. what is the risk of producing a gm crop which kills pests?
it will kill good insects as well.
3. why is the risk from carcinogens reduced in gm food?
because there are fewer traces of cancer inducing pesticides in the food.
4. what is the risk to someone who is allergic to a particular gene?
if that gene is transferred to another food, and the allergic person doesn’t know.
5. how does the amount of gm food in the us compare with the number of people who think it’s dangerous?