题目

Plants are very important living things. Life could not go on if there were no plants. This is because plants can make food from air, water and sunlight. Animals and man cannot make food from air, water and sunlight. Animals get their food by eating plants and other animals. Therefore animals and man need plants in order to live. This is why we find that there are so many plants around us. If you look carefully at the plants around you, you will find that there are two kinds of plants: flowering plants and non-flowering plants. Flowering plants can make seeds. The seeds are protected b 下列关于细胞分裂的叙述，正确的是 [　　] A．大肠杆菌在分裂过程中不出现纺锤体和染色体 B．高尔基体、线粒体、叶绿体在细胞分裂中活动旺盛 C．细胞内染色体上的蛋白质是在细胞分裂期合成的 D．基因型为Aa的体细胞，经有丝分裂产生两种子细胞