The need for effective coverage of secondary school syllabi is crucial in Kenya and the world at large. The problem which this study sought to determine was ineffective coverage of Kenya Certificate of Secondary Education (KCSE) Biology syllabus in secondary schools in the Sub County. The objective of this study was to establish the influence of teacher related factors on effective coverage of KCSE Biology syllabus in Secondary Schools in Rongai Sub-County, Kenya. The study was grounded on curriculum implementation theory and adopted correlational design. The study was based in Nakuru Rongai Sub-County secondary schools. The target population of this study comprised of 151 Biology teachers and 120 form four class secretaries. Census method was used to sample Biology teachers and class secretaries. In this study, content validity of the instrument was determined by research supervisors from Kabarak University who read the content, look at the items and ensured that they reflect the actual content area. This study used test retest method of determining reliability of research instrument. Data was collected using a questionnaire. The findings revealed that teacher related factors significantly influences on effective Coverage of Biology Syllabus (β = 0.390; p<0.05). The study concludes that factors such as teacher transfers, topics that are too wide in Biology and negative attitude towards some topics influence significantly effective syllabus coverage. It is herein recommended that teacher transfers should be managed appropriately in order to improve coverage of KCSE Biology Syllabus. Moreover, in-service training of teachers should be enhanced by Ministry of education in order to resolve negative attitude towards some topics. Finally, teachers should be adequately equipped with new technologies, pedagogical techniques and appropriate instructional resources in order to achieve effective coverage of Biology syllabus.
Keywords: Biology syllabus, Effective Coverage, Teacher-related factors