Unit 5 Look into Science
Lesson 29：DNA—The Story of You
【教学目标】
1．记忆单词DNA, blueprint, general, complex, twin, repeat, pattern, identify, related, grandson, granddaughter, instruction;短语in general, except for, e related to, billions of.
2．掌握重点句型:
（1）In general, blueprint is a drawing that shows how to put a hou together with many different parts.
（2）But building a living thing is far more complex than building a hou.
（3）You have your own unique DNA, but it repeats patterns from your parents' DNA.
envelope是什么意思（4）From your DNA, scientists can identify not only you, but also people who are related to you.
3．能够用英语向他人介绍自己所知道的有关DNA的知识.
4．能够理解课文内容并回答课后的问题.
【教学内容】
1．学会并能正确使用单词及短语:DNA, blueprint, general, complex, twin, repeat, pattern, identify, related, grandson, granddaughter, instruction, in general, except for, be related to, billions of.
2．能够运用下列句型:
（1）In general, blueprint is a drawing that shows how to put a hou together with many different parts.
（2）关于圣诞节的歌But building a living thing is far more complex than building a hou.
（3）You have your own unique DNA, but it repeats patterns from your parents' DNA.
（4）From your DNA, scientists can identify not only you, but also people who are related to you.
【教学重难点】
1．能够正确应用本课的重点词汇:DNA, blueprint, general, complex, twin, repeat, pattern, identify, related, grandson, granddaughter, instruction;掌握短语in general, except for, be related to, billions of.
2．能够用英语向他人介绍自己所知道的有关DNA的知识.
【教学思路】
思路一:以"DNA"为主题.通过展示图片 ,询问学生们"他们看起来一样吗?为什么一样?他们看起来不同吗?为什么不同?"引导学生们发现他们看起来相似的原因是由于DNA.通过设置学生感兴趣的话题导入新课 ,激发他们的学习兴趣 ,调动他们的积极性和主动性.
思路二:以"DNA"为主题.通过师生对话 ,直接导入本课话题DNA.通过小组合作探究 ,找出文中的重点短语和句子 ,共同解决疑难.
【教学准备】
教师在课前设计教学PPT,准备录音机和磁带,多媒体等.
【教学过程】
Ⅰ．Lead in
Leading in 情景1
T: Hello, class. Today we'll learn Lesson 29. (The teacher shows two pictures on PPT.)Plea look at the pictures. Are they look the same? Are there differences between them?
S1: ...
T: Why do some students look different? And why do cousins look similar?
Ss: Becau of DNA.关于母亲节的英语作文
英语改革英语四六级考试网T: Well done. Now let's learn Lesson 29: DNA—The Story of You.
设计意图:通过展示图片,设置学生感兴趣的问题,引出本课话题——DNA.激发了学生的学习兴趣.
Leading in 情景2
T: Good morning/afternoon, everyone. What is DNA? What does DNA stand for?
S1: DNA is something that all living things have.
S2: DNA carries the genetic information that makes every living thing what it is.
T: Very good. DNA is short for the full scientific term "deoxyribonucleic acid". That's hard t
o say. DNA is much easier. Every living thing has its own DNA. DNA holds the information and instructions for creating a living thing. For example, I have straight black hair becau part of the instructions in my DNA was to give me straight black hair. My grandmother has the same straight black hair. I have part of my grandmother's DNA.
设计意图:教师采用直接导入的方法,引出本课话题——DNA,使学生很直观地进入本课的学习,为下面的学习奠定基础.
Ⅱ．Prentation
The teacher shows the new words on PPT. Ask students to try to read the words. The students follow the teacher three times. Then give the students five minutes to remember the words. Let students spell and read them one by one.
设计意图:教师以PPT的形式呈现本课中出现的生词,领着学生们朗读并记忆,为下面的课文学习做好充分准备.
Ⅲ．Reading
1．Read the text aloud.
T: Boys and girls, it's our reading time. Plea read after the video and you should pay more attention to your pronunciation.
so far
设计意图:让学生大声朗读课文,对课文的意思有个大致的了解,对于培养学生的正确发音以及培养学生的语感都有重要作用.英文简介
2．Careful reading.
T: Boys and girls, now this time, I'll make the exerci a little more difficult. Read the lesson again and answer the questions.
自动翻译Show Let's Do It!
Read the lesson and answer the questions.consideration
（1）What is a blueprint?
（2）Which is more complex, building a living thing or building a hou?
（3）Do some twins have the same DNA?
（4）Is it possible to change your DNA?
（5）Who DNA is related to yours?
Keys:
（1）A blueprint is a drawing that shows how to put a hou together with many different parts.
（2）Building a living thing is far more complex than building a hou.
（3）Yes, they do.
（4）Yes, it is. In the future, scientists might be able to change our DNA.
（5）People who are related to me. For example, my parents and grandparents.
设计意图:要求学生认真阅读课文,把握课文信息,回答问题,对文章内容有更深层次的理解.
3．Read the text and find out main phras and ntences.
Main phras:
In general
Except for
Be related to
Billions of
Main ntences:
What can scientists do with DNA?
But building a living thing is far more complex than building a hou.
astro boyExcept for some twins, every living thing has its own unique DNA.
Some health problems can be caud by problems in your DNA.
