首页
登录
职称英语
About fifty years ago, plant physiologists set out to grow roots by themselv
About fifty years ago, plant physiologists set out to grow roots by themselv
游客
2025-02-02
10
管理
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 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. [br] The underlined word "intact" in Paragraph 2 is closest in meaning to ______.
选项
A、mature
B、wild
C、whole
D、tiny
答案
C
解析
词义题型。本句意为:对于分离出(孤立)的根所做的研究为了解根和芽作为一植物 ______的关系提供了帮助。当然intact应为:包括根和芽的植物整体;因此选项C为答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3940107.html
相关试题推荐
Somepeopleprefertoworkforthemselvesorownabusiness.Othersprefertowo
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
随机试题
[originaltext]Electronicdevicesarechangingthewaypeoplelistentomusic.B
Earlystudiesoftenconcludedthatthepublicwas______thepropagandisticinflue
Somepeopleseemtohaveaknack(诀窍)forlearninglanguages.Theycanpicku
A.骨折经治疗后,已超过一般愈合所需时间,骨折处仍有反常活动 B.X线片示两骨
有关肾盂造影时压迫腹部的叙述,错误的是A.压迫点为脐水平两侧 B.压迫球呈倒"
作为房地产经纪公司,在开展制定价格策略工作前,最重要的一个步骤是与开发商充分沟通
Heisassignedtooverseetheproduction
某工程,实施过程中发生如下事件: 事件1:监理合同签订后,监理单位技术负责
关于选项中,属于地下连续墙施工工序的有()。A、修筑导墙 B、搅拌机下沉
下列工程项目风险管理工作中,属于风险识别阶段的工作是()。A.分析各种风险的损
最新回复
(
0
)