1. Department of Science Education, Korea National University of Education, Cheongju-si, Republic of Korea
2. Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory, Emory University School of Medicine, Atlanta, GA, USA
3. Department of Biological Sciences, Pusan National University, Busan, Republic of Korea
4. Department of Biology Education, Korea National University of Education, Cheongju-si, Republic of Korea