文档介绍：第 2 页 / 总共4 页
英语专八改错练习题
One important outcome of the work on the expression of genes in developin 第 2 页 / 总共4 页
英语专八改错练习题
One important outcome of the work on the expression of genes in developing embryos is sure to be knowledge that can help preventing birth defects. Just as promising 26 is the possibility of
unraveling the complicated writing 27 of the brain. A mechanic gets valuable insight how an 28 automobile works by rebuilding car engines; similarly, neuroscientists can learn how the brain
functions from 29 the way it is put together. The next step pursuing the 30 goal is to find out how the blueprint genes, the home box genes, control the expression of other genes that
create the valves and piston of the working cerebral engine.
The protein encoded by the latter genes could change the 31 stickiness of the cell surface, the shape of the cell or its metabolism to create the characteristic peculiar to, say, neurons or
neural-crest cell. Surface proteins may be the 32 mechanism, whereby similar programmed cells stick together to form specific structures; they might also sense 33the local environment to
第 2 页 / 总共4 页
help the cell decide what is to do.
Clarifying those mechanisms