I've taught General Biology for several years in a university, which is an advanced course compared to the age range provided here. So I feel confident and excited to provide the following.
The course will cover:
Week 1: The digestive system
             The circulatory system
Week 2: The respiratory system
             The urinary system
Week 3: The muscular system
             The skeletal system
Week 4: The nervous system
              The immune system
             
             
In 45 minutes session, the topic will be taught clearly with advanced level of education that suits the age range. I will use a lot of colored and labeled figures that help students understand what is taught, as well as slides. During each session, students will learn about the main organs and the organs' functions in each system, example how we digest food and get rid of wastes, how we move our muscles, how our body produces urine, etc...
At the end of this course, learners will finally have a good idea about the systems so that whenever they hear a term related, or been asked a question, they will definitely know what to say.
I highly recommend the interaction of students with their teacher during the class. There is no need for student's knowledge about the topics.