草履虫的培养研究

文章通过研究不同的温度、pH值和培养液对草履虫生长的影响,总结出在现有条件下草履虫的简便有效培养方法.实验结果显示草履虫在不同温度条件下生长繁殖速度不同:15℃培养的草履虫个体大,游动较缓慢,适合于显微结构的观察;25℃可用于草履虫的中长期培养;35℃草履虫繁殖快,可用于草履虫的快速繁殖.在9种培养液中第9号培养液即"河水稻草煮液+米饭粒,最有利于草履虫的生长繁殖.pH值为7.0左右时草履虫的生长速度最快,且峰值期维持的时间最长.总结出培养草履虫的简捷有效方法,为草履虫培养提供相关参考.     

不同培养液对大草履虫生长的影响

大草履虫(Paramecium caudatum)是动物学教学和实验生物学的重要材料,不同的培养液对草履虫生长有影响.本试验选取狗尾草、玉米芯、小麦粒,玉米粒、白糖等较为常见材料,制成不同浓度培养液来培养大草履虫.以观察它们对大草履虫种群生长和个体形态的影响,以期找到既分布广泛又理想的培养材料.结果表明:玉米粒和玉米芯是理想的培养大草履虫的材料,其中1%玉米粒培养液的培养效果最好.     

草履虫的培养及探究其对某些物质的反应

观察草履虫的实验是学生最感兴趣的实验.实际教学中,学生在做这个实验的时候表现出的积极性最高,提出了很多问题.例如:草履虫除了用稻草液能培养外,用其他的物质能不能培养?草履虫喜欢吃什么,哪些物质会杀死水中的草履虫?即使下课了学生也久久不愿意离开,课余时间也主动要求来做实验……并尝试用自己设计的各种方法培养和繁殖草履虫.     

不同味精含量对草履虫生长繁殖的影响

用不同浓度的味精溶液培养草履虫,观察结果如下0.1%浓度的味精最适合草履虫生长;浓度为0.9%的培养液能让草履虫存在2天;浓度为1%的培养液不能让草履虫存活.     

快速培养草履虫的方法

用稻草液培养草履虫一般约经一周才可得到大量草履虫。作者经多次实验发现,用动物鲜组织液培养草履虫,可加快其繁殖速度,平均每天都在2代以上。当我们大量需要某种草履虫时,用动物鲜组织培养液培养是较好的方法。具体做法是:取新鲜猪肝或狗肝1克加200     

草履虫的采集、培养与观察

本文介绍了草履虫的采集，培养过程及观察方法等内容，对中学师生做好草履虫实验有参考价值。     

浅谈草履虫的培养与保种

现行人教版七年级《生物》上册中安排了《观察草履虫》的实验,所以每年秋冬季节上课都要用到草履虫,但是这段时间北方的天气凉,气温很低,到水中去采集草履虫不太可能,临时用稻草培养又有可能失败而贻误教学.为了培养学生的能力,保证生物实验教学的顺利进行,最好的方法是把用过的草履虫保存起来,以便随时取用.在多年的生物实验教学中,我们总结出草履虫的培养与保种的方法,现提出来与大家商榷.     

草履虫的保存方法

1．将采回的草履虫水样,经过提纯。培养繁殖（或实验课用完）之后,把培养液中的稻草（也可在培养液中放一些滤纸片）晾干。培养液中的草履虫便附着在稻草或滤纸片上。2．将晾干的稻草或滤纸片放在干净的容器里（广口瓶、烧杯等皆可）,在实验室里保存起来,以备下次上实验课时使用。要注意,不要让稻草或滤纸片发霉或受到污染。3．下次上课用草履虫时,可用通常培养草履虫的要求和方法,把保存带有草履虫的稻草或滤纸片放在制备的培养液中进行培养。大约经过1周左右,培养出的草履虫即可供上实验课使用了。如果用酵母作培养液刚效果更注。…     

探究草履虫对污水的净化作用

草履虫是原生动物的代表,它由一个细胞组成,一切生命活动都在一个细胞内完成。观察草履虫是动物教学的重要内容,对于培养学生的探究能力、提高学习热情、了解科学方法将会有较大帮助。该文用实验的方法探讨草履虫对污水的净化作用,旨在提高学生的研究能力。一、草履虫的培养1.方法1。选取离根端5cm左右的干稻草中部,剪成2cm左右的小段,数量约为20g,充水1000mL,放在明亮温暖的地方培养5-7d。由于稻草附有草履虫包囊,     

草履虫培养液的选择及浓度和pH值的影响

采用小麦、大米蔗糖、熟鸡蛋黄、稻草、酵母、猪肺等6种培养液，进行草履虫培养、繁殖的对比实验。实验结果表明，稻草和熟鸡蛋黄培养液为草履虫的理想培养液。另外，对上述2种理想培养液的不同浓度和稻草培养液的不同pH值影响草履虫的生长、繁殖进行了实验，实验显示，影响较为明显。稻草培养液的最适宜浓度为每1000mL水中加入10－20g稻草；熟鸡蛋黄培养液的最适宜浓度为每60mL冷开水中加入0．1－0．2g熟鸡蛋黄；稻草培养液的最适宜pH值为6.8-7.0。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.