. Scientists have not come close to understanding all the different kinds of lif

.

Scientists have not come close tounderstanding all the different kinds of life on the planet, but US researcherCraig Venter is already working on creating the first artificial（人造的）life.

Venter and his researchers made abreakthrough late last month, They successfully moved the DNA of one type ofbacteria(细菌) to ayeast cell（酵母）,changed it, then put it into another bacterial cell.

“Bacteria have systems that protect themfrom foreign DNA” Venter explained to the BBC, In the experiment, the teammanaged to block this system.

The experiment was performed on a simpletype of bacteria celled mycoplasma mycoides. The team took the bacteria’s genesand put them into a yeast cell.

Putting a DNA in a yeast cell allowed theteam to change the genes in this case, taking out a gene that was not necessaryfor the bacteria to live.   

They then put the gene into a host bacteriacell. The cell went on to divide normally, producing new healthy bacteria.

In January, the team created artificialgenes of a new type of bacteria. Their next goal is to put the artificial DNAinto a host cell to create a new species, according to a report in Sciencemagazine.

“lf we don’t make any errors, I think itshould work and we should have the first artificial species by the end of theyear.” Venter said in the report.

The first artificial life form is likely tobe a simple man-made bacteria, to prove that the technology can work.. But thatform will be followed by more complex bacteria that turn coal into cleanernatural gas, or algae  that can take in carbon dioxide and change it intofuel.

Many scientists think it’s good news tohave this artificial life, but others are worried that the technology to createnew organisms might end up in the wrong hands, with dangerous result.

57．Which of the following is true according to the text ?

A  Bacteria have systems that protectthem from yeast cell.

B  If we put a gene into a hostbacteria cell,the cell will not go on to divide as usual.

C  Venter and his researcherscompletely achieved all their goals.

D  All the scientists didn’t agree tothis artificial life.

58. What can we learn from the underlinedsentences?

A. Venter and his researchers had succeededin this project.

B. Venter predicted that they would makeerrors in the future,so he decided to give it up.

C. Venter would go on the study and he wasfull of confidence.

D. Venter was a clearer man but a littleshy.

59. Which of the following shows the orderof the passage ?

1.change the genes

2. put the gene into a host bacteria cell

3. moved the DNA of one type of bacteria toa yeast cell

4. The cell went on to divide normally

5. put it into another bacteria cell

A. 3-5-1-4-2    .              B. 3-5-1-2-4   C.4-2-5-1-3                     D. 2-3-5-1-4

60.What will be mentioned in the nextparagraph?

A. The wrong hands that created by theartificial life.

B. The advantages and disadvantages aboutthe artificial life.

C. The future about this project.

D. The author’s attitude.

试题答案

【答案】

57 D  58 C  59 B　６０　Ｂ

【解析】略