【单选题】

Designs on life Even if you’’re thinking big, you usually have to start small. It is especially true for a group of Swiss students who found that big means counting to infinity. The team was drawing up a blueprint for the world’’s first counting machine made entirely of biological parts.Although they had their sights on loftier numbers, they opted to go no higher than two. If the plan worked, it would be a proof-of-principle for a much larger tallyingdevice(计算装置).The group, from the Federal Institute of TechnologyETH) in Zurich, was one of 17 teams presenting their projects at the first international Intercollegiate GeneticallyEngineered Machine (IGEM) competition, held at the Massachusetts Institute of Technology (MIT) inCambridge on 5 and 6 November. The event attracted students from all over the world to design and build machines made entirely from biological components such as genes and proteins. They drew up grand designs for bacterialEtch-a-Sketches, photosensitive t-shirts, thermometers and sensors.And if none of the designs succeeded completely, that was more because of the limitations of the new-born science of synthetic biology than any lack of enthusiasm, creativity or hard work.Synthetic biologySynthetic biology aims to merge engineering approaches with biology. Researchers working at the most basic level are copying simple biological processes, such as the production of a protein from a gene. They break the process down into its component elements, such as a gene and the pieces ofDN

A、and other molecules that control its activity. They then string these elements together to build a module they know will behave in a particular way — say, oscillate between producing and not producing a protein, or produce a protein that can switch another module on or off.It is these kinds of components— oscillators (震荡器) and switches— that engineers order from suppliers and link together to build more complex electronic circuits and machines. Synthetic biologists are trying to develop a similar armoury of biological components, dubbedBioBricks, that can be inserted into any genetic circuit to carry out a particular function. Scientists at MIT have established a Registry of StandardBiological Parts, a catalogue ofBioBricks that theoretically can be ordered and plugged into a cell, just as resistors and transistors can be ordered and plugged into electronic circuitry. But it is hard to find scientists who are trained and interested in both biology and engineering to fuel the development of this new science. So, like true engineers, the founding synthetic biologists are trying to build their future colleagues from the ground up. To do so, they have commandeered a time-honoured engineering tradition: the student competition. The IGEM event began life as a project class for MIT students in 2003. Last year, it was thrown open to other US universities, and this year it went international. The organizers hope to attract 30 to 50 teams next year, including some fromAsi
A、Competitive cultureMuch like the robot competitions that tap into students’’ desire to build something cool, the IGEM jamborees (国际性少年大会) fire the participants’’ natural curiosity — hopefully encouraging biologists to learn something from engineers, and vice vers
A、"If you want to make something in this field, you can’’t just get some glue out and stick two cells together," says Randy Rettberg of MIT, who organized the competition. "You have to learn some biology to do it, and it’’s easy to do that during the competition because you know exactly why you’’re doing it."This year, the teams presented an eclectic selection of designs. Students from the University ofCambridge, UK, tried to make a circuit that could control the movement ofEscherichia coli bacteri
A、They aimed to engineer the bacteria to contain a switch governing their sensitivity to the sugar maltose. With the switch off, the microbes would ignore the sugar. Tripping