1994年河北省普通高中毕业会考生物实验考查中,要求考生重点掌握《叶绿体中色素的提取和分离实验》。为使学生在考查中获得最佳实验效果,实验教师对本实验做了如下改进: 1.把剪碎的叶片放于研钵中加少许二氧化硅和碳酸钙研磨,基本磨碎后再加1mL丙酮,再迅速充分研磨。这样做,减小丙酮挥发速度, In 1994, the Hebei Provincial Ordinary High School Graduation Association conducted an examination of biological experiments to require examinees to focus on the “Extraction and Separation of Pigments in Chloroplasts”. To enable students to obtain the best experimental results during the examination, the experimental teacher made the following improvements to this experiment: 1. Place the shredded leaves in a mortar and pestle, add a little silica and calcium carbonate, and grind them, then add 1 mL. Acetone and quickly grind thoroughly. In doing so, reducing the rate of acetone volatilization,