An Experimental Study On The Cohesion Of Biological "Core Concept" Teaching In "Molecules And Cells" From Junior To Senior Middle School Transitional Period

National biology Curriculum for compulsory education pointed out that biology teaching process should focus on the learning of "core concepts". In the teaching process, organizing and conducting teaching around the "core concept" can improve the teaching effectiveness, help students have a further understanding of the knowledge and contribute to application, migration, which show the importance of "core concept" teaching in biological subjects. Meanwhile, the delivery of "core concepts" not only should be highlighted in the classroom, but also should be undertaken in the process of delivery to achieve the core concepts' spiral development. However, with the deepening of the National Biology curriculum reform, and continuous textbook's revision, contradictions that how to connect the junior and senior middle school biology teaching are also emerging. In this research, the author distributes questionnaires to gather statistics to get a preliminary understanding of cohesion of the junior and senior middle school biology teaching. According to the result, in Guangxi, most students show great enthusiasm for biology, but their biology scores haven't any significant improvement. Most students are confused in biological concepts learning. They do not understand the core concepts, so they don't know what to do in the examination. The main reason for this is lack of cohesion in junior and senior middle school biology teaching. On one hand, junior high school teachers do not pay important attention to the processing of "core concept" and do not train students' core concept learning capacity, not aware what they have taught today brings an important effect on students when they rise into high school; on the behalf of students, they haven't developed a good learning habit, obviously not well memorizing what they have learn t in middle school, and isn't able to adapt to the concept learning in high school. On the other hand, most high school teachers aren't familiar with the junior high school's biology textbook, for lacking exchange and cannot correctly evaluate students' knowledge level, which lead to no growing point for the introduction of new knowledge, disconnection between teaching content and teaching method and disjoint between students and the teaching process. All these are bad for students'development. Therefore, how to effectively connect the "core concept" learning in junior and senior middle school is an important and urgent issue.In view of the above situation, this essay carry out a research about the "core concept cohesion in molecular and cell during the period of junior to senior middle school". This research will use National biology Curriculum for compulsory education as a reference, and compare the concepts in the first year senior middle school biology textbook with the 50 core concepts in the compulsory phase to find out the similar concepts. Based on connotation and denotation of concept presented in the textbook, the "core concept" during the period of junior to senior middle school can be divided into three main categories: vertical deepening concept, horizontal oriented concept and no obvious changes'concept. By analyzing the junior to senior middle school's biology text book, the author sums up seven similar concepts, such as cell, cell membrane, organelles, nucleus, cell respiration, photosynthesis, cell cycle. Besides, cell membrane, nucleus, and cell cycle belong to vertical deepening concept; organelles and cell respiration belong to horizontal oriented concept; and cell and photosynthesis belong to no obvious changes'concept. After the classification, according to different concepts' present pattern in the textbook and supporting material, the author analyzes the characteristics of these three kinds of concepts in cohesion. Then, based on the new curriculum reform, this essay puts forward the corresponding teaching strategies:(1)as for the vertical deepening concept, teacher should pay attention to basic knowledge learning, activate students' existing knowledge, promote the deepening of connotation concept; (2)as for the horizontal oriented concept, teacher should help the students learn to reorganize the concept, compare the similarities and differences between the concept, realizing the broadening of the concept; (3)As for the no obvious changes'concept, teacher should pay attention to the learning of supporting material, let students learn to apply what they have learned into reality, and cultivate students' emotional attitude and values.Finally, the writer select nucleus and organelles and photosynthesis from the above three categories to make teaching design, apply to practical teaching, and do teaching analysis accordingly, hoping to help middle school teachers in the process of concept teaching, and make a contribution to the cohesion of junior and senior middle school for key concept teaching.