ABSTRACT

The study investigated the Impacts of problem-solving and discussion teaching methods on students? achievement across ability levels in genetics. The study adopted a pretest-posttest quasi-experimental design with non-equivalent control group. The sample for the study consisted of 122 senior secondary III biology students. Purposive sampling was used to select four schools in Gombe education zone. The instrument used for the study is the Genetics Achievement Test (GAT) designed by the researcher. Section A of the instrument contained 20 multiple-choice items, section B contained 2 essay questions all for the measurement of students? achievement in genetics. Four research questions and four hypotheses were formulated to guide the study. The hypotheses were tested at 0.05 level of significance. The data collected were analyzed using mean and standard deviation and ANCOVA statistical tools. The results showed that ability level of students significantly influence achievement in genetics. The high ability students outperformed their medium and low ability students. Gender was not a significant factor.

CHAPTER ONE

INTRODUCTION
Background of the Study
Science has been regarded as the bedrock upon which the modern day technological breakthrough is built. Countries all over the world, especially the developing ones like Nigeria, are striving hard to develop technologically and scientifically. Nwagbo in Usman (2010) explained science as an intellectual activity carried out by humans, designed to discover information about the natural world in which we live and to discover the ways in which this information can be organized to benefit human race. According to Feynman (2011), science has become such an indispensable tool that no nation, developed or developing, wishing to progress in socio-economic sphere will afford to relegate the learning of science in schools to the background. The Federal Republic of Nigeria (FRN) in its National Policy on Education (FME, 2004:19) identified the goals of science education to include:
? Acquisition of knowledge, skills, inquiry and rational mind for conduct of good life.
? Produce scientist for national development
? Service studies in technology and the cause of technological advancement
? Understanding of the physical world, the forms and conduct of life and
? Provide knowledge and understanding of the complexity of the physical world, the forms and conduct of life.

Science comprises the basic disciplines such as biology, chemistry, physics and mathematics. The Federal Ministry of Education (FME, 2013) identified biology among the
core-science subjects offered at the Senior School Certificate Examination (SSCE) level., Ramalingam, (2003) defined biology as one of the branches of science that involves the study of living things ranging from microscopic cellular molecules to the biosphere which encompasses the earth surface.
Importance of biology as highlighted by Maduabum (2009:13) is stated as follows:
? helping individuals to understand the parts of his/her body and their functions,
? enabling one to question superstition due to sustained interest arising from comprehension of the cause of events,
? understanding and appreciating life,
? bringing into focus the need to maintain good health,
? promoting the individual for choice of careers,
? to inculcate in the individual scientific skills and attitudes in his approach to personal and societal problem,
? impart factual knowledge and stimulate scientific reflective thinking so as to produce a better informed individual.

In spite of these enormous importance that biology provides, biology results in most certified examinations like, Senior School Certificate Examination (SSCE) conducted by both the West African Examinations Council (WAEC) and the National Examinations Council (NECO).