生物学是一门以实验为基础的学科,在每年理科综合试卷和生物单科试卷中实验题或以实验为背景的试题分值几乎占到了总分的一半。遗传和变异是中学生物教学的重点和难点,也是历年高考的热点,该部分试题在高考试卷中所占分值比例往往较大。现将近几年试题中出现的与遗传和变异有关的 Biology is an experiment-based discipline. In the annual science examinations and biobiological examination papers, the test questions or the test questions with the background of the experiment account for almost half of the total scores. Genetics and mutations are the focus and difficulty of biology teaching in middle schools, and they are also hot spots in college entrance examinations over the years. The proportion of test scores in high test papers is often larger. In recent years, genetic and variation-related