问题
单项选择题
组成mRNA分子只有四种单核苷酸，但却能组成多少种密码子？（）
A、64种
B、20种
C、32种
D、75种
E、16种
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
组成mRNA分子只有四种单核苷酸，但却能组成多少种密码子？（）
A、64种
B、20种
C、32种
D、75种
E、16种
参考答案：A
| 填空题。 | |
2. Lily is a good girl, she always listens to her teacher ________ in class . 3. There is no plant life ________ air or water. 4. Elephants and whales are the largest ________ animals on land. 5. After you tell me about your school, I know ________ about it. 6. Neighbours were ________ to find the old man dead in his bedroom. 7. My little sister is fond of ________ after her baby cat. 8. This kind of frog is poisonous enough ________ about 2, 200 people. 9. The postcards belong to Tom and Daniel's, they are ________. 10. After reading the storybook, I find it very ________. |