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
2024-01-02
57
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 scientists found what the isolated roots need is ______
选项
A、quite natural
B、sugar, minerals and vitamins
C、some rare vitamins
D、organic nitrogen compounds
答案
B
解析
见第一段第三句:They required sugar and the usual minerals and vitamins.所以选项B是答案。
转载请注明原文地址:https://www.tihaiku.com/zcyy/3325995.html
相关试题推荐
Fromcolonialtimes,UnitedStatespropertyownersagreedtotaxthemselvesont
Somepeoplechoosefriendswhoaredifferentfromthemselves.Otherschoose
Somepeopleprefertoworkforthemselvesorownabusiness.Othersprefertowo
Sincetheexecutiveteamsofbothfirmshavecommittedthemselvestothedeal,t
Withnowaytoconfirmwhetherthose"friends"arewhotheyrepresentthemselves
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
Aboutfiftyyearsago,plantphysiologistssetouttogrowrootsbythemselv
随机试题
NewYorkwasoncethemurdercapitaloftheworld.Thankstothezero-tolera
Readthefollowingpassageandfillineachblankwithoneword.Choosethecorr
[A]Weapplyforcreditformanyreasons—maybeit’stobuyanewcar,house,comp
在民用建筑的供暖设计中,哪个部位不应设置散热器?()A.楼梯间 B.两道外
A.医源性 B.牙源性 C.损伤性 D.血源性 E.腺源性脐带感染导致婴
下列各项,不属盆腔淤血综合征的中医常见证型的是()A.肝肾亏损型 B.寒
西洋参药材来源于A:伞形科B:石竹科C:豆科D:毛茛科E:五加科
某混凝土试块强度值不满足规范要求,但经法定检测单位对混凝土实体强度经过法定检测后
个人汽车贷款中,所购车辆为二手车的,贷款额度不得超过()。A.70% B
对土料场的质量检查和控制中,( )的检查和控制最为重要。A.土块大小 B.杂质
最新回复
(
0
)