Even though ulcers appear to run in families, lifestyle plays more of a role than genetic factors in causing the illness, according to a report in the April 13th Journal of Internal Medicine. In particular, smoking and stress in men and the regular use of pain-releasing medicines in women were linked with an increased risk of developing an ulcer.
Overall, 61% of ulcer risk appears to be due to environmental factors, such as smoking, and the remaining 39% is due to genes according to Dr. Ismo Raiha of the University of Turky and colleagues at the University of Helsinki, Finland. Some researchers had suggested that families may spread Helicobacteria pylori, the bacteria that can cause ulcers. However, the new study suggests this is unlikely, according to the report.
Raiha and colleagues studied data from more than 13,000 pairs of twins to examine the roles of genetic and environmental factors in the origin of peptic ulcer disease, they explain. Both twins were more likely to develop an ulcer if the pair were genetically the same as compared with a pair of fraternal twins, suggesting that there must be some genetic susceptibility to ulcer development.
However, the risk was no greater in twins living together compared with twins living apart, suggesting that shared exposure to H. pylori was not to blame. Environment effects were not due to factors shared by family members, and they were related to smoking and stress in men and the use of analgesics in women, the authors wrote. The minor effects of shared environment to disease liability do not support the concept that the grouping of risk factors, such as H. pylori infection, would explain the genetic factor of peptic ulcer disease, they concluded.
1. According to the passage, which of the following is a very likely cause of ulcer in men?
A) Smoking and stress.
B) Drinking and smoking.
C) Genes and children.
D) Use of a certain medicine.
2. What factors contribute to over half the ulcers?
A) Hereditary factors.
B) Economic factors.
C) Environmental factors.
D) Genetic factors.
3. In relation to ulcers, experts study twins in order to examine
A) the roles of genetic factors.
B) the roles of environmental factors.
C) the roles of both factors.
D) the roles of brotherhood.
4. What does environmental effects in the fifth paragraph refer to?
A) A clean environment with no smoke and dust surrounding the living area.
B) Smoking and stress in men and use of pain-killing medicine in Women.
C) Factors shared by family members such as genes and the food they eat.
D) Shared exposure to H. pylori infection in the unclean environment.
5. The passage argues that
A) ulcers are related to genes.
B) ulcers are related to lifestyle.
C) ulcers appear in men and women.
D) ulcers are caused by pylori infection.
参考答案:A、 C、 C、 B、 B
中考英语复习资料:英语单项选择之命题特点及相应对策
中考英语知识点:中考英语不规则动词表3
中考英语复习资料:人称代词的句子角色及主宾格替换
中考英语复习资料:中考英语真题分类汇编--完形填空1
中考英语知识点:时间介词、可数和不可数名词
中考英语复习资料:中考英语复习积累句型
中考英语复习资料:英语减少词法错误
中考英语复习资料:中考英语易混词语用法讲解---all whole
中考英语复习资料:中考英语真题分类汇编--完形填空2
中考英语知识点:一般疑问句的四类句型
中考英语复习资料:中考英语书面表达必备常用过渡词汇
中考英语易混词语用法讲解:used to/be used to
中考英语复习资料:中考英语易混词语用法讲解--suggest insist
中考英语知识点:中考英语非谓语动词过关必知
中考英语复习资料:时间介词、可数和不可数名词
中考英语复习资料:名师指点--如何学好英语语法?
中考英语复习资料:中考英语动词时态复习考点2
中考英语知识点:中考英语语法复习——部分倒装
中考英语复习资料:词形变换练习题1
中考英语复习资料:中考英语完型填空做不好如何提高?
中考英语复习资料:语法练习7
中考英语知识点:中考英语词汇专项复习单词填空
中考英语知识点:英语时态的用法之二
中考英语复习资料:由turn、play构成的词组
中考英语知识点:为何中考英语完形填空最会错
中考英语知识点:怎样学好英语被动语态
中考英语复习资料:中考英语句型转换题四大诀窍归纳
中考英语知识点:中考英语短文填空练习1
中考英语知识点:with+宾语+宾语补足语
中考英语代词用法:相互代词
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |