Unit 5 Look into Science Lesson 29 DNA—The Story of You课件

课件14张PPT。Lesson 29DNA---The Story of YouThink about it!
What do you know about DNA?
2. What can scientists do with DNA?Presentation:This is the shape of DNA. Do you think it’s magic?“DNA” is short for deoxyribonucleic acid.The two girls are twins. Maybe they have the identical DNA. [identical（adj) -----identify (v.)]Why?Fang Zuming looks like his father—Cheng Long. Read the lesson and answer the questions：What is a blueprint?
Which is more complex, building a living thing or building a house?
Do some twins have the same DNA?
Is it possible to change your DNA?
Whose DNA is related to yours?Language Points:1.Are there differences between you and them? 你和他们之间有什么不同吗?
【辨析】between与among
between常用于两者之间，among一般指三者或三者以上.
Jack sits between Lin Tao and Bob.
I was among the crowd. 我处在人群中。2.You use it to build a house.你用它来建造房子。
use的用法 use…to do sth. 用……做某事
He is using a knife to cut bread. 他正用小刀切面包。
【注意】 use的形容词是useful，它是由use加后缀-ful构成的。如：
Is the fridge very useful? 这台冰箱很有用吗？3.DNA is a pattern, too. DNA也是一种模型。
too表示“也”时,通常置于句末，其前用逗号隔开。
【辨析】too与either
too与either都表示“也”，其区别是too用于肯定句，表示“也”；either用于否定句，表示“也不”。他们通常都位于句末，其前用逗号隔开。如：
He has a sister, too. 他也有个小妹妹。
He doesn’t have a knife, either. 他也没有小刀。4. Except for identical twins, each living thing has its own unique DNA.
除了同卵双胞胎之外，每个生物都有它唯一的DNA。
1)except for除……以外，只是
He is a good man except for hot temper.
除了脾气暴躁外，他是个好人。2)own的用法adj. 自己的（用在所有格后面，加强语气） She makes all her own clothes.
她所有的衣服都是自己做的。
vt. 有；拥有 Who owns the bike?
这辆自行车是谁的？
【友情提示】owner n. 所有人；物主
He is the owner of the house.
他是这座房子的主人。Practice:Fill in each blank with the proper word.
1. This is the __________(identify) hotel that we stayed in
last year.
2. Your brothers are people _________(relate) to you.
3. Do you know who is the _________(own) of the house?
4. Your body uses this pattern _________ (build) itself.
5. You have your own DNA, but it repeats the patterns
from your __________(parent) DNA.
6. Some health problems come from your family’s DNA.
_________(science) can look for these problems in your
DNA.identicalrelatedownerto buildparents’Scientists根据汉语意思完成句子，每空一词：
1. 我们用蓝图建造房子。
We _______ a blueprint ______ _______ a house.
2. 除了窗子小外,这座房子很漂亮。
The house is beautiful ______ _____ the small
windows.
3. 你的头发和皮肤有同样的DNA。
Your hair has ______ _______ _______ _____ your skin.
4. 她不但会唱歌，而且会跳舞。
She can _____ ______ sing ______ ________ dance.use to buildexcept forthe same DNA asnot onlybut alsoHomework
Make a summary
What have you known about “DNA” now? What can scientists do with DNA?