Abstract
The study investigated the effects of student?s improvised instructional materials on students? achievement in Biology. This study became necessary because of the unavailability of instructional materials for teaching biology in the secondary schools. The study employed a quasi experimental design, specifically the pretest ? posttest non equivalent group design. One hundred and forty SSI students from potiskum Education Zone from 2 schools randomly drawn from public primary schools in Potiskum education zone of Yobe State formed sample of the study. Three experts validated the instrument Biology Achievement Test (BAT). Five research questions were answered and five hypotheses were tested. The data were analyzed using mean, standard deviation and ANCOVA. The results revealed that students taught using improvised instructional materials performed better than students taught using conventional material; male students did not perform better than their female counterparts in Biology; rural students performed better than urban students in biology; The results do not suggest ordinal interaction effect between mode of method and gender on students? achievement in biology. This was because at all the levels of gender, the mean scores were higher for student?s improvised instructional material; the result suggests ordinal interaction effects between modes of method and location on students? achievement in Biology; this was because at all the levels of location, the mean scores were higher for student?s improvised instructional material compared to conventional materials with lower mean scores; there was significant difference in the mean score of students taught using students improvised instructional material and those taught using conventional instructional materials; there was no significant difference in the mean achievement scores of male and female students in biology; there was significant difference in the mean achievement scores of urban and rural students in biology; The interaction effect of method and gender on students mean achievement scores in Biology was, not statistically significant. The interaction effect of method and location on students? mean achievement scores in Biology was, not statistically significant. Based on the findings and implications, it was recommended that teaching of Biology in secondary school should be conducted in a manner that students will effectively understand and learn the concept taught. It was suggested that further research could be carried out on this topic using true experimental research.

CHAPTER ONE
INTRODUCTION
Background of the Study
Science is the bedrock on which modern day technological breakthrough is hinged. Different authors according to their own understanding have defined Science. Igwe (2003) defined science as a systematic study of the nature of the behaviour of the material and physical universe through observation, experimentation, measurement and recording. In addition, Esu (2004) defined science as a systematic, precise, objective way to study the natural world. Science is often an exciting and satisfying enterprise that requires creativity, skill and insight based on this Fape (2007) defined science as rationally structured knowledge about nature, which embraces systematic methods of positive attitudes for its acquisition, teaching, learning and application.
The major goal of science education is to develop scientifically literate individuals that are concerned with high competence for rational thoughts and actions. The objectives of science education in this country according to Maduekwe (2006) include the need to prepare students to observe and explore the environment, explain simple natural phenomena, develop scientific attitudes including curiosity, critical reflection and objectivity, apply the skills and knowledge gained through science to solve everyday problems in the environment, develop self-confidence and self-reliance through problem solving activities in science.
In recent times, countries all over the world, especially the developing ones like Nigeria, are striving hard to develop technologically and scientifically, since the world is turning Scientific and all proper functioning of lives depend greatly on Science. According to Ogunleye (2006), Science is a dynamic human activity concerned with understanding the workings of our world. This understanding helps man to know more about the universe. Without the application of science, it would have been difficult for man to explore the other planets of the universe. Science comprises the basic disciplines such as Physics, Chemistry, Mathematics and Biology.
Biology is one of the science subjects that senior secondary school students offer at the senior levels in the Nigerian secondary schools, (FRN, 2004). Biology is a very important science subject and a requirement for further learning of a number of science-related professional courses like medicine, agriculture, pharmacy, etc. In contemporary Nigeria, greater emphasis is placed on science and technological development. As a result, students are being encouraged to take up science-related subjects. Today, Biology pervades literally every field of human endeavour, and plays a fundamental role in educational advancement. This is seen in all the technological advancement in the world today, which is because of scientific investigations. However, the issue remains that in most secondary schools in Nigeria, there is high rate of failure in the subject.
Studies have shown that secondary school students are exhibiting low interest in Biology (Esiobu, 2005). This low interest of students in biology has been traced to poor achievement in examinations. In our match towards scientific and technological advancement, we need nothing short of good achievement in biology at all levels of schooling. Unfortunately, achievement of students in biology at the end of the secondary school has not improved in the last decade (Umoinyang, 1999). Folorunso (2004) has linked poor achievement trend in biology particularly to the lack of instructional resources in schools due to poor funding of schools. The poor funding of schools has hindered the principals from providing the teachers with adequate instructional resources.
The National Policy on Education (FME, 2004) emphasizes the need for teaching and learning of science processes and principles. The policy recommends practical, exploratory and experimental methods of teaching. In this regards, Okebukola (2004) stated that the basic tools that science uses in the learning of science processes are the instructional materials.
Studies have shown that the use of instructional materials have improved achievement (George, 2008) and Nwagbo (2006). Instructional materials are wide varieties of equipment and materials use for teaching and learning by teachers to stimulate self-activity on the part of the students. The teaching of Biology without instructional materials may certainly result in poor academic achievement. Poor academic achievement in Biology could also be attributed to many factors such as, low interest of students in biology, inadequate motivation from teacher, poor incentives to biology teachers, lack of adequate supply of instructional material, lack of qualified teachers, and use of teacher centered instructional strategies, inadequate use of instructional materials and use of abstract standardized materials. Among these factors, teacher?s use of abstract standardized instructional strategy is considered as an important factor in this study.
This implies that the mastery of Biology concepts might not be fully achieved without the use of instructional resources that the students are abreast with. The teaching of Biology without instructional materials may certainly result in poor academic achievement. Folorunso (2004) observed that there is lack of adequate and appropriate instructional resources for effective teaching of Biology in schools. For Ibitoye and Fape (2007), the poor achievement in biology was traced to poor usage of instructional resources for biology teaching and learning, poor state of infrastructure facilities, large class size, poor teaching, use of faulty assessment practice, and inadequacy of quality teachers. According to Okebukola (2004), the poor state of laboratory facilities and inadequate use of instructional materials has constituted a cog in the wheel of students? achievement in Biology in the Senior School Examination. The verbal exposition does not promote skill acquisition, objectivity, and critical thinking abilities that will enable the child to function effectively in the society. This according to the researcher leads to poor achievement of students in the subject. Okebukola and Jegede (1986) stressed that a professionally qualified Biology teacher no matter how well trained, would be unable to put his ideas into practice if the school setting lacks the equipment and material resources necessary for him or her to translate his competence into reality.
The report of West African Examination Council (WAEC) on the Senior Secondary School Certificate Examination (SSCE) (2011) on student enrolment and performance in Nigeria by subject, grade, and sex revealed low enrolment of girls for science subjects as well as low academic achievement in biology and other science subjects and the persistent poor achievement of students in biology.