(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:                                  

Plant scientists consider them as fruit. Most other people think of them as vegetables. Whatever you call tomatoes, there are many different kinds of this popular and healthy food.
There are two groups of the plants. Small tomato plants grow to about one meter. They can be planted rather close together. Some short kinds do not require special care and are often gotten crop by machines. Large tomato plants can grow over two meters tall. They also produce larger fruits.
People who grow only a few plants can place wire cages around each one. The cage can be made of wire fence material. The cage helps the plant grow taller and produce a better crop.
Tomatoes often need extra calcium (Ca), or the fruits may be ruined. Add lime to the soil can solve this problem. Dry lands may also ruin the fruits. Tomatoes need water regularly. The soil should never dry out completely. Dried grass or leaves placed around the plant can help hold water in the soil and stop the growth of unwanted plants.
Tomatoes are native to South America. The tomato is a member of the potato family. The leaves of the plant are poisonous, like the leaves of its relatives. Before the 18th century, people grew tomatoes only as pretty plants. They called the bright red fruit a “love apple”, but would not eat it.
【小题1】Which of the following is right about the small tomato plants?
A. They can grow to about 2 meters.    
B. They can’t be planted close together.
C. Some of them don’t require special care.
【小题2】People place wire cages around the plant in order to ___________.
A. protect the plant from being taken by others.
B. help the plant grow taller and produce a better crop
C. keep the plant from being eaten by animals
【小题3】The underlined word “ruin” probably means “___________”.
A. grow     B. destroy      C. stop    
【小题4】 People often give tomatoes extra calcium by ___________.
A. adding lime to the soil          B. watering the plant regularly
C. putting dried grass around the plant
【小题5】What can we learn from the passage?
A. Tomatoes are native to North America.
B. The leaves of the plant can also be eaten.
C. Americans began to eat tomatoes from the 18th century.

As you are soon on your way to Eastern Europe, here are a few tips on what you should pack. In general, pack lightly, with only the most basic clothes. People dress casually(随便地) in Eastern Europe, so you don’t need to bring along your smartest clothing.

Batteries: If your camera, flash, or other appliances run on batteries, bring enough supply along. Certain types of batteries don’t exist in Eastern Europe, and those that do often don’t last very long.

Cash: We have found it good to have supply of small-unit U.S. bills($1and $5) to use in hard–currency stores, to buy international train tickets, etc. The hard–currency stores never seem to have the right change.

Electric Current Adapter(转换器): If you bring any appliances, remember that the electricity in Eastern Europe uses 220 volts A.C., not the standard 110 volts of North America. A 110 volts appliance will soon burn out when attached to an unchanged 220-volt plug.

Language Tools: One of Europe’s biggest challenges is communicating with the local people since their languages are so different from our own. To help overcome difficulties, you might buy phrasebooks before you go — you won’t find them once you are in Eastern Europe.

Money Belt: A money belt is especially helpful when you have many documents to carry around ( as you always do in Eastern Europe). The best one we find is made by Eagle Greek Travel Gear, 143 Cedros Ave. (P. O. box 651), Solona Beach, CA 92075 (tel. 619/755 – 9399, or toll free 800/874 – 9925) outside California.

Traveler’s Checks: These are necessary. Bring your traveler’s checks in small to medium unit ($10, $20, or $50) to change a little bit at a time, so as not to be left with a lot of local money. To be on the safe side, be sure to copy down the check numbers in two places, just in case something happens to the checks.

1.How many tips are mentioned in the passage?

A.6                B.7                C.8                D.9

2.Which of the following things may be the biggest challenge in Eastern Europe?

A.Appliances.        B.Money.           C.Language.         D.Clothes.

3.Which of the following statements is NOT a fact according to the passage?

A. No shop in Eastern Europe accepts hard currency.

B. Travelers may need to carry many documents in Eastern Europe.

C. The electricity in Eastern Europe uses 220 volts A.C.

D. Eastern European languages can be a problem to foreign travelers.

4.What’s the writer’s purpose of writing this passage?

A.To tell you it’s not easy to stay in Eastern Europe.

B.To give you some advice on what you should pack when you’re in Eastern Europe.

C.To tell you something about the life in Eastern Europe.

D.To show you the life in Eastern Europe is different from that in your country.

5.What do the underlined words “change” and “check” probably mean according to the given dictionary entries(词条)?

change

1. [V] to become different 改变;变化

2. [V] to exchange money into the money of another country 兑换

3. [U] the money that you get back when you have paid for sth giving more money than the amount it costs 找给的零钱;找头

check

1. [V] to examine sth to see if it is correct, safe or acceptable 检查;审查

2. [C] an act of making sure that sth is safe, correct or in good condition by examining it 检查;查看

3. [C] a printed form that you can write on and sign as a way of paying for sth instead of using money 支票

A.1; 3              B.3; 3              C.2; 3              D.2; 2

 

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