Step 1 Review 第一步 复习 1.(让学生快速说出节日名称.) T: There are a lot of festivals in the world. What are they?Please tell us quickly. S1: Halloween, Mid-autumn Festival, Teacher’s Day... S2: Easter, Mother’s Day, April Fool’s Day... 查看更多

 

题目列表(包括答案和解析)

(10分)植物具有向重力生长的特性,下列是研究根向重力生长机理的两个实验。
实验一:将空白琼脂和含EDTA的琼脂做成帽状,分别套在甲、乙两组玉米胚根的根冠外(示意图如下)。提示:EDTA的作用是去除与其临接部位的 Ca2+

将胚根水平放置培养一定时间后,观察到甲组胚根向重力(下)生长,乙组胚根水平生长。根据上述实验结果,得出实验结论:                               
  实验二:水平放置的胚根弯曲向下生长,与根冠近地侧的Ca2+浓度明显高于远地侧有关。研究表明,根总是朝着Ca 2+浓度高的方向弯曲生长。为验证这一结论,有人设计了下列实验方案。请根据提供的实验材料和用具,写出第二步及以后的实验步骤和实验结果,并回答问题。
(1)实验材料和用具:胚根等长的萌发玉米种子,空白琼脂帽,含EDTA的琼脂帽,上面部分含Ca2+的琼脂帽(水平方向),培养皿等。
(2)实验步骤:
  第一步:取若干个培养皿,在每个培养皿中放置适量的萌发玉米种子,按实验一中乙组的方法处理胚根一定时间后,移去根冠外的琼脂帽。然后将培养皿平均分成两组,编号为 A组、B 组。 
  第二步:                                                            
  第三步:                                                            
(3)实验结果:                                                         
(4)科学家进一步证实,根冠中生长素的分布受Ca2+浓度影响,当胚根水平放置时,重力诱导Ca2+向根冠下侧移动,导致近地侧的生长素浓度比远地侧高。请分析胚根的生长素分布与向重力生长的关系:                                  

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阅读理解

  Overcoming shyness is not impossible.Let's discuss the steps to bring you out of shyness.

  Step 1

  Overcoming shyness is mainly a case of mind over matter.If you're afraid to do it, then do it again.The more you come to talk with people, the easier it will become.You may also find that it's not as difficult as you thought anyway.Just talk to people a little more every day.

  Step 2

  It sometimes helps to try to imagine(想象)yourself as another person.Think about it, do you get shy when someone else walks up to talk to another? Of course you don't.Think of yourself just as another somebody else and it'll make it a little easier.

  Step 3

  Dress up.The better you look, the more confident you'll feel.Feeling good about your appearance can greatly reduce shyness.

  Step 4

  If you're up to stage, try to imagine that you're somewhere else.Maybe in the comforts of your own living room.Tell yourself that the people in the audience are only people.

(1)

The first step mainly tells us ________.

[  ]

A.

we should talk to people as much as possible

B.

it's difficult to get over shyness

C.

we'll be shy when talking to more people

D.

we are shy because we don't think carefully

(2)

What does the underlined word "reduce" mean in this passage?

[  ]

A.

喜欢

B.

减少

C.

增大

D.

防治

(3)

The fourth step tells us ________.

[  ]

A.

it's easy to speak in our living room

B.

it's easy to speak to only people

C.

what to think of when speaking on stage

D.

when you can speak on stage

(4)

What's the best title for this passage?

[  ]

A.

How to Get on Well with Others

B.

How to Get over Shyness

C.

How to Act on Stage

D.

How to Make Friends with Others

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阅读理解

  Overcoming(克服)shyness is not impossible.The following steps may be helpful.

  Step 1

  Overcoming shyness is mainly a case of mind over matter.If you’re afraid to do it, you will get much shyer when doing it.The more you came to talk with people, the easier it will become.You may also find that it’s not as difficult as you thought anyway.Just talk to people a little more every day.

  Step 2

  It sometimes helps to try to imagine you as another person.Think about this:Do you get shy when someone else walks up to talk to another? Of course you don’t.Think of yourself as just another somebody else and it’ll make it a little easier.

  Step 3

  Dress to impress.The better you look, the more confident you’ll feel.Feeling good about your appearance can greatly reduce shyness.

  Step 4

  If you’re up on stage try to imagine that you’re somewhere else.Maybe in your own comfortable living room.Tell yourself that the people in the audience are really no big deal.They’re ONLY people.

(1)

The first step mainly tells us _________.

[  ]

A.

we should talk to people as much as possible

B.

it’s difficult to get over shyness

C.

we’ll be shy when talking to more people

D.

we are shy because we don’t think carefully

(2)

The second step tells us it’s _________ to think of yourself as another person.

[  ]

A.

unnecessary

B.

interesting

C.

useful

D.

difficult

(3)

What does the underlined word “reduce” mean in this passage?

[  ]

A.

喜欢

B.

减少

C.

增大

D.

防治

(4)

We can learn from the fourth step that _________.

[  ]

A.

it’s easy to speak in our living-room

B.

it’s easy to speak to only people

C.

what to think of when speaking on stage

D.

when you can speak on stage

(5)

What’s the best title of this passage?

[  ]

A.

How to get over shyness

B.

How to speak in public

C.

Don’t look on you as yourself

D.

How to feel good about yourself

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阅读理解

  When you’re curious(好奇)about something, and want to know more about it, you can use the way of asking questions.Asking questions is the first step to make discoveries and find interesting answers.The steps below can guide you during the research(研究).

  Step 1  On a note card or piece of paper, write down the subject that you are interested in.Just get the main idea down.For example, you might write:Discover more about dinosaurs.

  Step 2  Next, stop and think for a moment about what you already know about your subject.List what you already know like the sentences below:

  (1)Dinosaurs lived long before human beings appeared.

  (2)Dinosaurs lived on the earth for more than 150 million years.

  (3)Some dinosaurs fed on plants, some on meat.

  Step 3  What can you do with what you want to learn? By asking questions.On your paper, start writing down questions about the dinosaurs as you think of them:

  (1)What’s the best weather for dinosaurs to live in?

  (2)How many kinds of dinosaurs are there?

  (3)Have dinosaurs really disappeared?

  Step 4  Armed with your list of questions, you can now go to the nearest library or computer to begin your research.As you learn more about your subject, you’ll probably discover some new questions.For example, you might discover that dinosaurs disappeared about 65 million years ago.Why? What happened? Asking new questions can help you research your subject more widely.

  The next time you find something interesting to research, take time to organize(组织)your thinking by asking good questions.And remember-learning more always brings more questions.

(1)

When you do some research, you should take the following steps:________.

①list what you want to know  ②choose a research subject

③list what you already know  ④discover new problems

[  ]

A.

④③①②

B.

①④③②

C.

②③①④

D.

③②④①

(2)

From the passage, we know ________.

[  ]

A.

dinosaurs appeared after human beings

B.

not all the dinosaurs fed on meat

C.

dinosaurs lived on the earth for 65 million years

D.

dinosaurs liked warm seasons

(3)

What does “Armed with your list of questions” mean?

[  ]

A.

Putting your list of questions under your arm

B.

Discussing your questions with your classmates

C.

Writing down your list of questions

D.

Taking your list of questions with you

(4)

According to the passage, which one is true?________.

[  ]

A.

You can find all the answers online

B.

Learn more, and you’ll have no questions

C.

Asking questions is the only way for research

D.

During the research, you may keep finding new questions

(5)

The best title for this passage is “________”.

[  ]

A.

Discovering Dinosaurs

B.

Asking Good Questions

C.

Finding Subjects

D.

Learning Steps

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(10分)生长素的主要作用是促进细胞纵向伸长,其作用机理如图所示,请回答下列问题:

(1)生长素作用的第一步是与细胞膜上的受体结合,形成“激素—受体复合物”,这一过程体现了细胞膜的_________功能。
(2)被激活的“激素—受体复合物”能引起内质网释放Ca2 + , Ca2 +促使细胞内的 H+        的方式运往细胞外,增加了细胞壁的延展性,使细胞壁对细胞的压力减小,导致细胞吸水、体积增大而发生不可逆增长。细胞在生长过程中体积变化最大的细胞器是________。实验发现,细胞在持续生长过程中,细胞壁的厚度能基本保持不变,出现这种现象的原因是由于_____________(填细胞器)为细胞壁添加了新的成分。
(3) Ca2 +还能激活细胞中的转录因子,它进入细胞核后,能引起____酶催化 mRNA 的合成。
(4)生长素促进根系生长的最适宜浓度要比茎低得多,稍高浓度的生长素能促进乙烯的生物合成,从而抑制了根的伸长,这说明生长素的作用具有__________。
(5)科学家研究发现紫外线可以抑制植物生长,原因是紫外线增加了植物体内吲哚乙酸氧化酶的活性,从而促进了生长素氧化为3—亚甲基氧代吲哚,而后者没有促进细胞伸长的作用。现在提供生长状况相同的健康的小麦幼苗若干作为实验材料,请完成下列实验方案,以验证紫外线抑制植物生长与生长素的氧化有关。
步骤 1 :将小麦幼苗平均分为甲组和乙组。
步骤 2 :给予甲组适宜的可见光光照,给予乙组_______________________光照。
步骤 3 :观察两组幼苗的________________,并测量___________的含量。
预测实验结果: ______________________________________________________。

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