B9M2DNAtheSecretofLife教学设计

一、百度图片

本课时的话题是DNA——生命的奥秘，在课文的第一部分介绍了DNA是什么以及哪两位科学家发现了DNA，所以在课前预习学案中充分利用百度图片形象展示DNA结构图及James Watson和Francis Crick两位科学家的合影。在课文学习的导入环节，利用网络上搜索的“抱错孩子”的新闻图片，激发学生的学习兴趣，引出文本话题，并为任务的实现和目标的最终达成奠定了基础。

二、网络文字材料

为了让学生在课文学习之前真正热好身，我们从网站上搜索了多篇关于James Watson和Francis Crick的英文材料，整合成一篇短文，以阅读表达的形式呈现在课前预习学案的“热身加油站”环节，精心设置了归纳文本主旨大意、理顺行文特点、补全句子和翻译句子四个练习。

The names James Watson and Francis Crick aren’t exactly known in every

household, but these two scientists have profoundly influenced our lives. They were the first people to describe the structure of deoxyribonucleic acid(脱氧核糖核酸), better known to us as _____, which determines everything from the color of our eyes to the shape of our fingernails. Because of them we now have a much deeper understanding of how the human body works.

James Watson was born in Chicago in 1928. He graduated from University with a degree in Zoology. In 1950 he received his Ph.D. In his doctoral work, he began studying bacteria. During this study he became interested in the structure of DNA. Francis Crick was born in 1918 in England. He studied physics in college. He became interested in X-ray diffraction(X射线衍射) on proteins, a subject that also fascinated Watson. Watson and Crick met in 1951 and the two soon realized they were joined by a common goal—DNA research. In 1953 the two were able to prove the double-helix (双螺旋) structure of DNA by using X-ray diffraction techniques. They were awarded the Nobel Prize in 1962. Without their pioneering research, the structure of DNA might still be a mystery. Even though their collaboration(合作) lasted only a few years, their achievement was enough to tie their names together forever in the history of science. They paved the way for the early detection of genetic diseases such as sickle-cell anemia(镰刀型细胞贫血), and for new scientific leaps such as animal cloning. 1. What’s the main idea of the passage? 2. How is the whole passage developed?

3. Fill in the blank with suitable words. (no more than two words) 4. Translate the underlined sentence into Chinese.