首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
About fifty years ago, plant physiologists set out to grow roots by themselves in solutions in laboratory flasks. The scientists
About fifty years ago, plant physiologists set out to grow roots by themselves in solutions in laboratory flasks. The scientists
admin
2015-04-18
34
问题
About fifty years ago, plant physiologists set out to grow roots by
themselves
in solutions in laboratory flasks. The scientists found that the nutrition of isolated roots was quite simple. They required sugar and the usual minerals and vitamins. However, they did not require organic nitrogen compounds. These roots got along free on mineral inorganic nitrogen. Roots are capable of making their own proteins and other organic compounds. These activities by roots require energy, of course. The process of respiration uses sugar to make the high energy compound ATP, which drives the biochemical reactions. Respiration also requires oxygen. Highly active roots require a good deal of oxygen.
The study of isolated roots has provided an understanding of the relationship between shoots and roots in
intact
plants. The leaves of the shoots provide the roots with sugar and vitamins, and the roots provide the shoots with water and minerals. In addition, roots can provide the shoots with organic nitrogen compounds. This
comes in handy
for the growth of buds in the early spring when leaves are not yet functioning. Once leaves begin photosynthesizing, they produce protein, but only mature leaves can "export" protein to the rest of the plant in the form of amino acids.
Roots have the ability to______.
选项
A、make proteins
B、obtain fresh air
C、produce inorganic nitrogen
D、carry out activities without energy
答案
A
解析
本题考查细节理解。根据文章第一段第六句“Roots are capable of making theirown proteins and other organic compounds.”可知,本题答案是A。
转载请注明原文地址:https://kaotiyun.com/show/ZmwO777K
本试题收录于:
CATTI三级笔译综合能力题库翻译专业资格(CATTI)分类
0
CATTI三级笔译综合能力
翻译专业资格(CATTI)
相关试题推荐
"Civilization"Between4000and3000B.C.,significanttechnologicaldevelopmentsbegantotransformtheNeolithictowns.Th
InfluenzaandVaccinesThereisnospecificcureforinfluenza.Recommendedtreatmentusuallyconsistsofbedrestandincre
GENERALSYSTEMSTHEORY1TheGreekword"systema"meansunion,andscientistsusetheword"system"todescribe
OverlandtransportintheUnitedStateswasstillextremelyprimitivein1790.Roadswerefewandshort,usuallyextendingfrom
NarratorListentoaconversationbetweentwostudents.Nowgetreadytoanswerthequestions.Youmayuseyournotesto
Whydoestheprofessormentiontheexpressions"mothertongue"and"motherese"?
Inordertosupporthimself,studentBfoundaneveningjobinasupermarket.Now,theproblemisthatstudentBcan’ttakethe
Anintroductorysentenceforabriefsummaryofthepassageisprovidedbelow.CompletethesummarybyselectingtheTHREEanswe
Theheartisastriatedmuscle______contractasquicklyastheskeletalmuscles.
JohnandIhavejustbeentellingstoriestwoofus.
随机试题
连翘的归经是
DNA重组过程中所使用的酶类统称为工具酶,限制性核酸内切酶(限制酶),是一类能识别双链DNA分子中某种特定核苷酸序列,并由此切割DNA双链结构的核酸酶,下列有关限制酶的叙述,除哪个外,都是正确的
项目目标可分解为工期目标、成本目标和()。
劳动者在试用期内单方解除劳动合同,应提前()日通知用人单位。
下列各项中,()不属于产品整体范畴。
某客户计划申购某只新股,若每股发行价格为13己,则该客户证券账户中至少需要有()元用来申购(不考虑税费)。
公共外交是政府外交的重要补充,其基础是普通公众,目的在于改善外国公众对本国的态度,影响外国政府对本国的政策。日前,我国每年出境游8000万人次以上,普通游客的言行可以带来公共外交的效果,如举止有度、谈吐得体有正面效果,大声喧哗、不守秩序有负面影响。由此可见
奥林匹克运动发展到今天这样的规模,其意义大大超出竞技体育的______。正是因为有众多国家、地区运动员的参加,才推动了奥林匹克运动自身的______和壮大,而且通过各国运动员的友谊和交往,对全世界的和平以及全人类的进步事业作出了难能可贵的贡献。填入
2011年,全国研究与试验发展(R&D)经费支出8687亿元,比2002年增长5.7倍,占国内生产总值的比重由1.07%上升到1.84%。2011年,研究与试验发展人员全时当量288.3万人年,比2002年增长1.8倍。技术市场成交额4764亿元,
Perhapsmorethananythingelse,scientistsareeagertofindoutifMartianlifeexistedinthepast—orstillexists.【C1】______
最新回复
(
0
)