不要。A teacher in charge of a class is called a class teacher./ A teacher who is in charge of a class is called a class teacher. 前者是介词词组修饰a teacher,后者是定语从句。定语从句也是个句子，是从属地位，所以会有动词。
当然不要了 这个句子的主干就是a teacher is called a class teacher，这个定语从句是省略的形式，补完整就是who is in charge of 。反正只要找到主干就行，不是主谓宾就是主系表。另外补充一定要区分开in charge of 和in the charge of。回答完毕。
