Unit 5 Look into Science-lesson 29 dna---the story of you教案

Lesson 29: DNA—The Story of You
I. Learning aims:
Master the new words:
DNA, blueprint, general, complex, twin, copy, repeat, pattern, identify, related, grandson, granddaughter, instruction
II. Learning important and difficult points:
1) In general, a blueprint is a drawing that shows how to put a house together with many different parts.
2) But building a living thing is far more complex than building a house.
3) Except for some twins, every living thing has its own unique DNA.
4) From your DNA, scientists can identify not only you, but also people who are related to you.
5) Your DNA has billions of instructions that explain why you are the way you are.
Language Points:
1. copy
【用法】作可数名词，意为“复制品、一本、一册”，复数形式是copies。
【举例】①This is just a copy. Have you found it 这只是一个复制品。你发现了吗？② I borrowed two copies of magazines from the library. 我从图书馆借了辆本杂志。
【用法】作及物动词，意为“复制、抄写”，后加名词或代词作宾语。
【举例】Have you finished copying the words 你抄写完单词了吗？
【应用】根据括号中所给汉语用适当词语填空。
We don’t need any ____________（复制品）. Write them by hand.
答案：copies。表示“复制品”用名词copy，且这里是复数形式。
2. repeat
【用法】作及物动词，意为“重复、重述”， 后加名词或代词作宾语。
【举例】What about repeat the text for another time 再重复一遍课文怎么样？
【拓展】在口语中，当没听清对方的话或没看清对方的动作要求对法重复时，为了表示客套，要用Pardon？或 Beg your pardon 或I beg your pardon
【举例】Pardon I didn’t hear your words clearly. 请重复一遍好吗？我没听清你的话。
【应用】根据括号中所给汉语用适当词语填空。
The teacher ___________（重复）the sentences and I knew its meaning at last.
答案：repeated。表示“重复”用动词repeat，且这里是一般过去时。
语句详解
1. But building a living thing is far more complex than building a house. 但是构建一个有生命的东西比建一座房子复杂得多。
【用法】比较级前可以用much, even, still, far, a bit, a little, a lot 等词加以修饰。
【举例】①This unit is much easier than that one. 这个单元比那个单元容易得多。②This book is far more interesting than that one.这本书比那本书有趣得多。
答案：a little taller。此处用副词a little作状语，修饰后面的比较级taller。
2. Except for some twins, every living thing has its own unique DNA. 除了一些双胞胎外，所有有生命的东西都在自己独特的DNA。
【用法】except for用于表示对主要部分的肯定和对局部的否定。它不表示同类事物之间的关系，其意思是“除了……以外、除去为了……、如果不是”。
【举例】①Smith is a good man, except for his bad temper. 史密斯除了脾气不好外，是个好人。②Mother wouldn’t give him any money except for books and stationery. 除了买书和文具外，妈妈不给他任何钱。③Except for you, I would pass the exam. 如果不是你，我就会通过考试。
3. From your DNA, scientists can identify not only you, but also people who are related to you. 根据你的DNA, 科学家不仅能辨别出你，而且能辨别出与你有关系的人。
【用法】not only…but also…是等立连词，意思是“不但……而且……”，它可以连接句中句子成分相同的部分，如果用它连接主语时，谓语动词应该以but also后面的主语为准。
【举例】①She can sing not only Chinese songs but also English songs. 她不仅会唱中文歌曲，还会唱英文歌曲。②Not only I but also she has finished the work. 不仅我完成了工作，她也完成了工作。
【用法】短语be related to意为“与……有关系”，后加名词或代词作介词to的宾语。
【举例】I think Danny is related to this matter. 我想丹尼与这件事情有关。