问题 单项选择题

研究发现,Ⅱ型糖尿病患者体内胰岛素含量正常,但不能有效地降低血糖。对于Ⅱ型糖尿病病因的描述正确的是:()

A.不能降低血糖的原因是胰岛素不足

B.不能降低血糖的原因是胰高血糖素太多

C.患者细胞识别胰岛素的受体异常或太少

D.患者摄入了过多糖类

答案

参考答案:C

解析:

胰岛素作用于靶细胞的机理是:胰岛素与靶细胞膜上的受体结合,调节靶细胞的代谢,降低血糖。由于题干明确指出该患者体内胰岛素含量正常,A项错误;所以胰岛素含量正常但血糖浓度依然很高,说明患者体内的胰岛素不能发挥作用,可能是靶细胞缺乏识别胰岛素的受体或受体太少,C项正确;根据胰岛素的作用机理,B、D两项不是产生糖尿病的病因,B、D项错误。

考点:本题考查糖尿病的产生原因,意在考查考生能运用所学知识与观点,通过比较、分析与综合等方法对某些生物学问题进行解释、推理,做出合理的判断的能力。

完形填空
完形填空。
     Today is Sunday. Mary and her mother  1  to do the shopping. Her mother wants to buy something for
supper. Mary wants to buy a new skirt and some school things. They come  to a new shop.
      "What does your shop sell?" Mary asks."A lot of things,"  2  in the shop says."You can buy food, drinks,
clothes in our shop and school things, too."
       Mary and her mother go in. There are many people in the shop. Mary wants a skirt.
       "  3  do you want?" asks the girl in the shop.
       "White." 
       "Have a look  4  this one. It's nice."
       "How much is the skirt?"
       " 5  eighty yuan." 
       "That's too expensive. Can I find a cheap one?"
       "What about the green one? It  6  nice. And it's  7  thirty yuan.
       "OK,  8  a lot."
       "You are welcome."
       After that, Mary buys some school things, too.  9  mother buys a lot of food, like bread, cakes, meat
and fish.  10  get home very late.
( )1. A. going     
( )2. A. a man     
( )3. A. What color
( )4. A. on        
( )5. A. They're   
( )6. A. sound     
( )7. A. too       
( )8. A. thank     
( )9. A. Her       
( )10. A. She      
B. go      
B. a boy   
B. What    
B. for     
B. It's    
B. sounds  
B. only    
B. thank me
B. His     
B. They    
C. wants    
C. the girls
C. How      
C. at       
C. Is       
C. look     
C. also     
C. thanks   
C. She      
C. Her mother
D. walks      
D. the girl   
D. How much   
D. in         
D. Its        
D. looks      
D. yet        
D. thanks you 
D. He                                   
D. We         
辨析题