Hey aspirant, b. Ed is a two year educational course in which there are 4 semesters and here teaching internship phase is also there,  see every university has its own curriculum,please mentioned the college or university where you want tom take admission,here let's take an example of Himachal pradesh university,you can take chemistry and zoo as your subject, but in curriculum there are different subject you have to pass all these subjects ,for teaching internship phase your subjects are divided into life science and physical science in which you have to do teaching internship and teach students in schools. In life science both botany and zoology chapters of clases up to 10 and for physical  sciences for medical students you have to prepare lessons plans for chemistry chapters  . For further info visit the link
https://www.careers360.com/courses/b-ed-bachelor-of-education