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
2013-11-07
76
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 fine 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
conies 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
细节题型。见第一段第六句:Roots are capable of making their own proteins and otherorganic compounds.所以选项A是答案。
转载请注明原文地址:https://www.kaotiyun.com/show/lIwO777K
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
FilmExchangesinAmerica’sEarlyMovieIndustry1.Motionpictureswereexhibitedtothepublicinthelate1800s,thoughthe
Readashortpassageandlistentopartofalectureonthesametopic.AboriginalPeopleAlthoughthefirstinhabitants
Manypeoplehavelearnedaforeignlanguageintheirowncountry;othershavelearnedaforeignlanguageinthecountryinwhich
StudiesbyPark,Burgess,andotherChicago-schoolsociologistsshowedhownewgroupsofimmigrantstendedtobeconcentratedin
"TheHydrologicCycle"Thehydrologiccycleisthetransferofwaterfromtheoceanstotheatmospheretothelandandbackt
Thecountrywillnolongerbeplaguedbyturmoil.
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommunication.Theconvenienceandefficiencyofelec
Marketingis______justdistributinggoodsfromthemanufacturertothefinalcustomer.
Thecombinedevidenceofhistoryandecologyseemstosupportonegeneraldeduction:thelessviolentthemanmadechanges,the
随机试题
()高压针形截止阀的“低进高出”是指当阀体手轮向上时,侧向孔位置相对低的一侧为阀门的进口(来压方向),相对较高的一侧为出口。
渔父莞尔而笑,鼓枻而去。
持续性房颤是指房颤持续时间超过
一名溺水游客被救出后,神志不清,呼吸停止,口唇发绀,需口对口人工呼吸的先决条件是
煤与瓦斯突出多数发生在构造带、煤层遭受严重破坏的地带、煤层产状发生显著变化的地带、煤层硬度系数小于()的软煤层中。
锅炉用高压无缝钢管的制造材料是()。
投资者会要求对承担信用风险进行补偿,这导致市场上信用风险较高的企业债券与同期限、同息票率的国债相比价格更低,收益率更高,这个高出的收益率称为()。
SNMPv1是一个不安全的协议,管理站(Manager)与代理(Agent)之间通过______进行身份认证,由于认证信息没有加密,所以是不安全的。
将R1中的8位二进制数存储到由R2+1指示的单元,并自动更新地址的ARM指令是()。
昨天你已经答应我了,绝对不能反悔。
最新回复
(
0
)