Reading and vocabulary名师教学设计1

Cloning and DNA Teaching aims: 1.

To master the following words; 2.

To understand the text clearly; 3.

To ensure the Ss can express their own opinions about “clone or not clone?”

Teaching difficulties: To ensure the Ss express their own opinions correctly. Teaching aids: PPT and computer. Step 1 Warming up 1.

Introduce Dolly (1997-2003) 2.

To review some technical terms by inviting individual student. Step 2 Fast reading 1.

Have Ss read the passage quickly and answer the following questions. (1). What is DNA? (2). What is clone? (3). What’re the characteristics of stem cells? 2. Read the passage again and say which paragraph describe: (1).When the structure of DNA was discovered? (2).How to clone something? (3).Four possible reasons for cloning. Step 3 Detailed reading 1.

Para.1---Para.2 Time 1866 1953 1973 2.

Para 4---Para. 8 (1).How many reasons are mentioned for scientists to clone humans? An Italian doctor wants to ... Scientist Mendel Watson and crick Cohen and Boyer Discovery Both parent plants have influenced the genetic make-up of the new plant The structure of acid DNA A procedure to use enzymes to unzip the DNA, to cut out a sequence of genes and finally insert them into the host cell and combine with its DNA.

Another reason is that... A further reason is to ... A fourth reason for cloning is that... (2).According to the passage,

what are the advantages and disadvantages of cloning? Advantages Cloning is an optional treatment for couples who find it difficult to have children. Disadvantages A clone would be under unknown psychological pressure throughout their childhood To reproduce the talents of exceptional It may possess new vices instead of existing human beings. virtues. To obtain a supply of stem cells. The embryo would then be wasted, which many people find unacceptable. Some scientists and farmers think it would be To rely on a few cloned animals or crops handy to clone. would restrict the biodiversity of the breed.

Step 4 Post-reading Cloning is a controversial topic in human society. There has been a lot of debate over whether or not cloning should be used. If you had the power, would you ban cloning or would you encourage it? Why？

Some useful expressions: Present yours idea: I’m for/ against cloning.

Support your idea with solid arguments: Firstly, Secondly, Thirdly,…

For one thing, For another…

What’s more, Moreover, In addition,…

Make a conclusion: In short, To sum up, In conclusion,…

Step 5 Homework

Have Ss write a short composition about “clone or not clone?”