Ⅰ. 阅读理解
Studying the DNA of 300 mice has flagged up genes which have been linked to hereditary (遗传的) sight loss for the first time. Researchers say because mice’s genes are so similar to humans’, their findings could lead to the treatment of more genetic diseases.
Scientists at the University of California, Davis studied information from a data bank of mice’s genetic material. They found 347 genes linked to eye problems, with just 86 of them having been studied in the past.
Only around 50 to 75 percent of hereditary eye diseases in human can be explained with present science. The researchers believe these hundreds of new genes found in mice could be a key to explaining—and therefore being able to treat the other 25—50 percent.
“This is extremely valuable for people with hereditary eye disease, ”said researcher Professor Ala Moshiri. “All researchers are going to start using these data. In the past, we knew the problem was there but we didn’t know where to look. Now eye centers can call back patients and screen them for these new genes. We expected that more and more of these genetic diseases will be treatable. ”Also, the fact is that more than 60 percent of eye problems at birth are ones resulting from the baby’s parents!
Thanks to data from the International Mouse Phenotyping Consortium (IMPC), which is trying to work out what every single gene in a mouse is responsible for, with the aim of translating it to humans, scientists are moving closer to figuring out all genetic causes of blindness. To do this, scientists separate a single gene from other ones at a time and then observe what effect it has on the mouse for a long time. This has so far been done more than 7, 000 times and has achieved great success. Researchers are now working alongside eye care centers in Texas and Iowa in order to compare the mice’s genes to those of patients.
【语篇概述】本文是一篇科普说明文。加州大学戴维斯分校的科学家们对小白鼠数百种的新基因进行了研究。研究的成果是解释人类遗传性眼病的关键。
1. How many hereditary-sight-loss-related genes were newly found?
A. 86. B. 261. C. 300. D. 347.
【解析】选B。推理判断题。根据第二段They found 347 genes linked to eye problems, with just 86 of them having been studied in the past. 可知, 他们发现347个基因与眼睛问题有关, 其中只有86个基因在过去被研究过。即新发现与遗传性失明相关的基因有: 347-86=261个。
2. Why is the percentage of genetic eye problems mentioned in Paragraph 3?
A. To show the significance of studying mice’s genes.
B. To prove mice’s genes are similar to humans’.
C. To warn the high risk level of suffering them.
D. To explain how common they are among people.
【解析】选A。细节理解题。由第三段The researchers believe these hundreds of new genes found in mice could be a key to explaining—and therefore being able to treat the other 25-50 percent. 可知, 研究人员认为, 在老鼠身上发现的数百种新基因可能是解释这一现象的关键, 因此能够治疗另外25%至50%的疾病。即第三段提到遗传性眼睛问题的百分比是为了展示研究老鼠基因的重要性。
3. What should scientists do first to unlock secrets of genetic blindness?
A. Compare humans’ genes with mice’s.
B. Recognize each gene’s role of humans.
C. Set apart a gene of a mouse each time.
D. Figure out each gene’s function of a mouse.
【解析】选C。细节理解题。由最后一段To do this, scientists separate a single gene from other ones at a time and then observe what effect it has on the mouse for a long time. 可知, 科学家们一次将一个基因从其他基因中分离出来, 然后观察它在很长一段时间内对老鼠有什么影响。即为了解开基因性失明的秘密, 科学家们首先应该每次从老鼠身上分离出一个基因。
4. What can be a suitable title for the text?
A. New Ways to Cure Sight Loss
B. Genes Found Behind Eye Problems
C. Genetic Diseases Discovered in Mice
D. Humans’ Genes Causing Eye Diseases
【解析】选B。主旨大意题。文章主要内容: 科学家发现在小白鼠身上发现的数百种新基因可能是解释人类遗传性眼部疾病的关键。
