2. 外语
  3. 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

admin2022-06-18  68
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.
The underlined word "photosynthesizing" in Paragraph 2 means_________.
选项 A、obtaining inorganic and organic compound
B、producing oxygen and protein
C、making sugar and vitamins
D、growing bigger and taller
答案C
解析 句意：一旦叶子开始光合作用，它们就会产生蛋白质。photosynthesize意为“进行光合作用”，所以选项B为答案。
转载请注明原文地址:https://kaotiyun.com/show/IbuO777K
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
随机试题
最新回复(0)