问题 问答题 简答题

何谓原生质体?如何获得原生质体?

答案

参考答案:G+细菌人为彻底去壁后仅由细胞膜包围的细胞生活体部分即为原生质体。获得的方法:用某选择性溶菌酶(如溶菌酶)以适当浓度处理G+细菌,经一定时间后,便可彻底去掉细胞壁;或者让G+细菌在一种特殊的环境中生长。例如将其培养在含一定浓度青霉素的培养基中,便可抑制细胞壁肽聚糖的合成而获得。

完形填空

阅读下面短文,并按照题目要求用英语问答问题(请注意问题后词数要求)。

Some countries are better than others at looking after the environment. In Europe, Germany(德国)and northem European countries work very hard to improve the environment. The people in Germany put their rubbish into different bags-paper in one bag, plastic in laws that do not allow people to burn too much coal. In the 1970s ,as people learned more about environmental problems, the “Green” movement(运动)began and soon spread all over Europe. The “Green ”movement tries to get governments to protect the environment. It collects information about how industry is damaging(毁坏)the environment and tells newspapers. 

小题1:Which countries in Europe work very hard to improve the environment? (within 5 words)

                                                                                          

小题2:Who put rubbish into different bags? (within 4 words)

                                                                                           

小题3:Can the people in Germany burn too much coal? (within 1 words)

                                                                                           

小题4:When did the “Green “movement begin? (within 3 words)

                                                                                           

小题5:What does the “Green”movement try to do?  (within 6 words)

                                                                                           

单项选择题