The purposes of this study were to investigate what biology content areas that biology teachers perceive as important but difficult for them to teach and the reasons they for perceptions. The investigator used a forty-item questionnaire to elicit information from one hundred and twelve biology teachers in Kwara State. The mean and standard deviation of each item were computed and rank ordered. Frequency counts were then used for the reasons given by the teachers. Most of the content areas perceived as important to teach belong to pure biology. The most frequent reason given was complexity, followed by lack of teaching aids, abstractness. sophistication, insufficient teaching experience and never studied the content areas in the university. Educators should help practicing and perspective biology teachers in dealing with content areas that are important but difficult to teach.    

Cognitive science is a fairly new field of research in which people from different disciplines seek to understand what constitutes intelligent behaviour in term of human knowledge. (Abimbola, 1987). Workers in this field seek to know how human beings store, retrieve and use knowledge, and how existing knowledge affects communication, learning and the performance of tasks such as comprehension and problem solving. The special area of interest of this author is how students’ existing conceptions, including traditional beliefs, affect their new learning, especially in biology. Studies in he above area of research usually have as basis assumptions of content importance and difficulty as perceived by the teachers’, students, external examiners, etc. Unfortunately, most of the research on students’ misconceptions in biology that are available in this field is from the developed countries. However, these seminal works by Okeke (1976), Taiwo (1976), Adeniyi (1983), Abimbola (1984), etc., are a beginning. Unfortunately, these studies largely have as basis, assumptions of contents important and difficulty as perceived by researchers from the developed countries that may not be relevant to the Nigerian situation. These assumptions may not always hold for the situation in Nigeria because of differences in curricular, teachers and students’ characteristics. To move the research progragmme forward in Nigeria, therefore, it is necessary to have the baseline data on the important content areas that are difficult for teachers to teach.   

The objectives of the present study were to answer the following questions: 1.  What biology content areas do biology teachers perceive as important for them to teach? 

2.  What biology content areas do biology teachers perceived as difficult for them to teach? 

3.  What biology content areas do biology teachers perceived as both important and difficult to teach?   

This study is significant because of the information it provides that relates to the curricular and instructional decisions that teachers must make daily. Such information is also useful in the continuing implementation of the current biology curricular.