冀教版九年级上册Unit 5 Look into Science Lesson 29 DNA—The Story of You 课件 (共21张PPT)

(共21张PPT)
Lesson 29
Unit 5
Look into Science
Curriculum words: blueprint, general, complex, twin, copy, repeat, pattern, identify, related, grandson
Useful expressions: In general, a blueprint is a drawing that shows how to put a house together with many different parts.
Functions: Master the new words: DNA, blueprint, general, complex, twin, copy, repeat, pattern, identify, related, grandson, granddaughter, instruction
Grammar: except for的用法
Sentences: But building a living thing is far more complex than building a house.Except for some twins, every living thing has its own unique DNA.
学习目标
What do you know about DNA
Lead-in
THINK ABOUT IT
What do you know about DNA
What can scientists do with DNA
新课讲授
Text presentation
When you build a house，you use a blueprint. What's a blueprint？In general，a blueprint is a drawing that shows how to put a house together with many different parts. DNA is the blueprint of life.
This is the shape of DNA. Do you think it's magic
But building a living thing is far more complex than building a house. It takes millions of years for nature to change the DNA in living things to make them fit the world they live in.
How tall are you？What colour are your eyes？What size are your feet All these things are strongly influenced by your DNA before you are born!
DNA is fantastic!
· Except for some twins，every living thing has its own unique DNA.
· Some health problems can be caused by problems in your DNA. Scientists can look for these problems and，sometimes，help you before you become sick. In the future，scientists might be able to change your DNA.
· There are copies of your DNA in every part of your body. For example， your finger has the same DNA as your hair.
·You have your own unique DNA，but it repeats patterns from your parents’ DNA. From your DNA，scientists can identify not only you，but also people who are related to you. Your parents and grandparents are related to you，and you have their DNA. When you have a grandson or granddaughter，he or she will have your DNA.
Your DNA has billions of instructions that explain why you are the way you are. It's one of the most amazing things on the earth!
Your DNA comes from your parents.
Read the lesson and answer the questions.
1
1．What is a blueprint
2．Which is more complex，building a living thing or building a house
3．Do some twins have the same DNA
4．Is it possible to change your DNA
5．Whose DNA is related to yours
A blueprint is a drawing that shows how to put a house together with many different parts.
Let 's Do It !
Building a living thing.
Yes, they do.
Yes. In the future, scientists might be able to change our DNA.
My parents' and my grandparents'.
Fill in the blanks with the phrases in the box.
2
in general　except for　not only…but also
related to 　even if　the same…as
1．Your homework is quite good ____________a few spelling mistakes.
2．________the young ________the old like pop music.
3．Kate's hair is__________ colour ______her sister's.
4．___________，women live longer than men.
5．________ many difficulties remain,we can overcome them.
6．Is wealth ___________ happiness
except for
Not only
but also
the same
In general　
Even if
related to
as
Complete the passage with the sentences in the box.
3
A．Their DNA can't combine.
B．We can make plants that are bad for pests.
C．They can even combine the DNA of a plant and an animal.
Changing DNA
Do you know DNA can be changed Have you ever seen a pig with a dog's body Of course not! Pigs and dogs can't have babies together. ______ But now，scientists can do it. Scientists can take DNA , from one kind of animal and put it into another kind of animal. They can design new plants By combining the DNA of other plants.________ Some scientists are worried. They say we need to know more about DNA before we start changing it. ________ But what if the plants are bad for humans，too
A
C
B
Is it a good idea to change the DNA of the food we eat Some people say doing this makes our food better. Others think it's too dangerous. Search the Internet for information and write down your ideas.
4
do with 处理
Point 1
do with与deal with都可表示“处理”。
do with常与what连用，而deal with常与how连用。
eg：I don't know what they do with the problem.
我不知道他们如何处理这个问题。
Language points
in general 通常；大体上
Point 2
generally adv.一般地；广泛地；普遍地。
generally speaking“大体而言；概括来说”。
eg：Generally speaking，your idea is right.
总的来说，你的想法是正确的。
In general，their cars are very reliable.
通常，他们的小汽车是很可靠的。
辨析 except，except for，besides与but
Point 3
except 意为“除了”，表示从整体中除去，不包括所除事物在内，除去的和非除去的是同类事物。一般不用于句首。
except for 意为“除了”，说明整个基本情况后，对细节加以纠正，其后一般接名词或名词性短语。
besides 意为“除了……之外还有”，包括所“除”的事物在内。
but 意为“除……外”，多用在no，nobody，who，where，all等词之后。
not only...but also... 不但……而且……
Point 4
(1) not only...but also...用于连接两个并列的成分，着重强调后者。(连接两个并列的主语)
eg：Not only Ma Lin but also Ma Long plays ping pong very well.
不但马琳而且马龙乒乓球打得也很好。
(2) not only...but also...连接两个并列主语时，谓语动词要与它最近的主语保持人称和数上的一致，即“就近原则”。
eg：Not only the boy but also his parents are staring at the screen.
不但那个男孩而且他的父母也正在盯着屏幕。
one of … ……之一
Point 5
one of… 意为“……之一”，后接可数名词复数作主语时，谓语动词用单数。如有形容词修饰one of后的名词时，形容词一般用最高级形式，最高级前应有定冠词the或形容词性物主代词。
eg：He is one of my best friends. 他是我最好的朋友之一。
One of my friends lives in Beijing. 我的一个朋友住在北京。
by /ba / prep. 通过……
Point 6
eg： I learn English by listening to the radio.
我通过听收音机学习英语。
by意为“用来；靠；通过”，表示方式或途径。
eg：They make their living by selling fish.
他们以卖鱼为生。
典 例
You can improve your English ________ practicing more.
A．by B．with C．of D．in
A
【点拨】本题考查介词的用法。by表示方式，“通过”； with“用；和……在一起”；of“关于；属于……的”； in“在……里”。由句意“你可以通过多练习提高你的英语。”可知，by表示方式，符合题意。
一、根据句意及首字母提示完成单词
1．Lucy and Lily are t______．They look the same.
2．In g________，women do it more easily than men.
3．It's important for you to r________the text.
4．Mike has a granddaughter and a g________．
5．Before you take this medicine, you must read the i_____________.
eneral
wins
epeat
当堂检测
randson
nstructions
二、单项选择
6．What did the police ________ that accident
A．deal in B．deal with C．do with D．do about
7．My article is good ________some spelling mistakes.
A．except B．except for C．Beside D．besides
8．From your DNA，scientists can identify you and the people ________ to you.
A．related B．relates C．relating D．relate
9．Not only you but also he _____ the secret.
A．knows B．know C．have known D．to know
C
B
A
A
课堂总结
Structure
In general, a blueprint is a drawing that shows how to put a house together with many different parts.
Key Words
blueprint, general, complex, twin, copy, repeat, pattern, identify, related, grandson
Key sentences
But building a living thing is far more complex than building a house. Except for some twins, every living thing has its own unique DNA.
Expressions
It's one of the most amazing things on the earth!