有丝分裂是细胞分裂的主要方式，也是学习减数分裂和遗传基本规律的基础。有丝分裂过程中染色体形态和数目的规律性变化，既是教学的重点，又因知识抽象，学生不易理解，所以也是教学难点。如何突破这一难点呢？笔者在进行“细胞有丝分裂”的教学时，始终抓住染色体的形态、数 Mitosis is the main form of cell division, and it is also the basis for learning the basic laws of meiosis and inheritance. The regular changes of chromosome morphology and number in the process of mitosis are not only the focus of teaching, but also because of knowledge abstraction, students are not easy to understand, so it is also a teaching difficulty. How to break this difficult point? In my teaching of “cell mitosis,” the author always seized the form and number of chromosomes.