题目

The connection between people and plants has long been the subject of scientific research. Recent studies have found positive effects. A study conducted in Youngstown，Ohio，for example, discovered that greener areas of the city experienced less crime. In another，employees were shown to be 15% more productive when their workplaces were decorated with houseplants.The engineers at the Massachusetts Institute of Technology(MIT)have taken it a step further changing the actual composition of plants in order to get them to perform diverse，even unusual functions. These include plants that have 9．如图为某人的一个体细胞及其中一条染色体组成示意图，据图判断下列叙述不正确的是（　　）A．一个DNA分子上有很多个基因B．一条染色体含有2个DNA分子C．染色体在细胞核中D．基因是遗传物质结构和功能的基本单位