论文部分内容阅读
(续 2 0 0 2年第 1期第 5 2页 )第 卷 (共 90分 )二 .简答题 (共 90分 )31.(8分 )科研人员给农作物施以 15N标记的肥料 ,结果在以此农作物为食物的羊尿中查出15N元素。请回答下列问题 :(1)含 15N的化肥是以状态从土壤进入根细胞的。根吸收矿质元素的主要部位是。(2 )含 15N的
(90 points) B. Short answer (90 points total) 31. (8 points) Researchers applied 15N-labeled fertilizers to crops and the results were as follows: 15N element is found in the urine of sheep as food for this crop. Please answer the following questions: (1) 15N fertilizers are in the state of entering the root cells from the soil. Root absorption of mineral elements is the main part. (2) Containing 15N