EFFECT OF PROBLEM SOLVING AND DISCOVERY POLICIES ON ATTITUDE, RETENTION AND PERFORMANCE IN GENETICS CONCEPTS AMONG SECONDARY SCHOOL STUDENTS IN ZARIA, KADUNA STATE NIGERIA  

ABSTRACT

This study investigated the impact of problemsolving and discovery strategies on attitude, retention and academic performance in genetic concepts among secodnary school students in Zaria, Nigeria. The research design for the study Quasi-experimental and control group involving pretest andposttest. The population of the study consisted of 527, (264 male and 263 female) students. Simple random sampling technique by balloting method was used to select three schools out of five co-educational schools. A sample of three hundred and forty-five (345) secondary school students consisting of 182 male and 163 female students were randomly selected and used for the study. The sample was divided into three groups – experimental and control groups. Both groups were pre-tested before the treatment, and post testedafter treatment. Two instruments were used for gathering data, Genetic Performance Test (GPT) with reliability co-efficient of r=0.87 and Students‟ Attitude to Genetics Questionnaire (SAGQ) with reliability co-efficient of r=0.79. Two statistical tools – Analysis of Variance (ANOVA) and Kruskal Wallis were used for analysing the data gathered at P≤0.05 level of significance. Findings revealed that students taught using problem-solving and discovery strategies performed better than those taught usinglecture method. From the means scores of problemsolving and discovery teaching strategy the problemsolving mean scores was 24.74 while discovery strategy was 25.78 which is the highest mean scores. This shows that discoverystrategy have more impact in enhancing students academic performance in genetics. The same results was obtained in their retention ability and attitude change. However, gender did not affect their performance in anyway in all the teaching strategies. Based on the findings recommendations were made one of which urged biology teachers to use problem-solving and discovery strategies to improve students perforance in teaching genetics genetics at secondary school.

 

 

CHAPTER ONE

THE PROBLEM

1.1        Introduction

Science education is an indispensable tool for national development because the economic and political strength of a nation is mostly assessed in terms of her performance in science and technology (Olarinoye 2001, Otuka 2006 & Wasagu 2007). In view of its importance to nation building, the Federal Government of Nigeria emphasized the teaching of science and technology at all levels of education in the country as stipulated in the National Policy on Education (FRN, 2013). This advocacy is sometimes inconsistent with various reform initiatives around the globe for both science and mathematics curricular and classroom practices. For instance, the need to develop students‟ understanding and scientific literacy by using inquiry and problem – solving experiences and skills acquisition, has been emphasized in the United States reform document of the

American Association for Advancement of Science (AAAS, 2006) and National Research Council (NRC, 2006) which are also adopted in the teaching of basic science such as Chemistry, Physics and Biology.

Biology is a branch of science that deals with the systematic study of life. Biology as a science subject, has many branches notably Zoology, study of animals and Botany:the study of plants. Biology has other concepts under it such as ecology, microbiology, evolution, genetics and many others. Biology serves as a pre-requisite or a core subject to many science disciplines notably human medicine, food technology, agriculture, pharmacy, veterinary medicine and health education. It is reflected as a requirement for admission into science-based courses at Universities, Colleges of Education, Polytechnics and other tertiary institutions.

In spite of the strategic position of Biology among other science and science related disciplines, students‟performance hasconsistently been below expectation and unimpressive.Oloyede (2008) reported that, the failure rate inBiology examination culminated in to the poor performances of students over the years. Biology is one of the natural sciences that the level of students‟ performance was below expectation. In this vein, the performance of students in science is reflected on how well they understood science concepts and it boiled down to how well the instructor is giving the instruction (Jegede, 1996). The performance of Biology students in SSCE examination in Kaduna state had been declining over the years as presented in Table 1.1

Table 1.1 Students Performance in Biology in Kaduna State WAEC  May/June 2012-2015

Years	Total Sat for Exams	% Pass	% Fail
2012	26,821	47.04	52.96
2013	34,852	41.95	58.05
2014	30,653	42.98	57.02
2015	50,896	47.83	52.17

Source: (West African Examination Council Chief Examiner’s Report 2012 – 2015)

The need to find solution to students‟ low performance in Biology is therefore an obvious factor as Damide (2000), Oloyede (2008) and Zayun (2008) opined that several factors have been advanced for the low performance of students in Biology. These include non-availability ofteaching and learning materials, abstract nature of some concepts in Biology, poor language skillson the part of both the teachers and the student societal factors, instruction and strategies employed by the teacher among others Oloyede (2008) observedthe students poor interest in Biology contributes substantially to the failure rate inBiology. The West African Examination Council (WAEC, 2010) examination report showed that students‟performances are generally low in Biology.

Ineffective instructional method of teaching as well as lack of practical work resulted into the poor performance of candidates in genetics at senior secondary school as observed by Okebukola (2000).The result also revealed that secondary school students perceived genetics as a difficult concept. This is as a result of the abstract nature of genetic concepts which makes the understanding difficult and resulting in poor performance (Lawal, 2009). The persistent poor performance in Biology at SSS levels need to be improved by using activity – based teaching strategies such as problem-solving, and discovery which allow active students‟ participation. This type of study is necessary because it encourages hands on activities needed for effective learning process at SSS level.Specifically, therefore, this study investigates what will be the impact of two constructivist teaching strategies: Problem solving and discovery teaching strategies on academic performance, retention, and attitude to genetic among Senior Secondary Schoolstudents. Previous researches were done on the use of activity based teaching strategy such as problem solving, discovery, collaboration separately but this research used the two strategies to find out which one is probably more appropriate in learning genetics concepts at secondary schools.

Genetics being an integral part of Biology syllabus constitutes the last aspect of senior secondary schools curriculum beside evolution and ecology. Consequently, the teachers find it difficult to teach the students genetic concepts appropriately due to its abstract nature. This contributes to the poor performance of students in Biology S.S.C.E as observed by WAEC and NECO Chief Examiners‟ Reports (2015). Also, Okeke (2010) observed that, lack of appropriate teaching strategies usually affect students‟ academic performance adversely in science subjects due to the fact that most of the contents of science subjects are all abstract and difficult to learn more especially genetics concepts among others. In view of the above, the study is aimed at providing strategies such as problem-solving and discovery strategy in teaching genetics at senior secondary schools which may probably have a far reaching effect in imparting knowledge to the Biology students and that could help to reduce the poor performance of students.

Genetics is a branch of Biology that deals with the study of heredity and variations, the principle that accounts for the diversity of organism (Kala, 2012). Also, according to Kala (2012),the understanding of genetics at colleges of education and universities very much depends on the pre-requisite of understanding of genetics concepts like the cell, its structure and functions among others. A good knowledge of genetics is very important to students of Biology and related courses such as genetic engineering, plant breeding etc., most especially in their later years of study (Okebukola, 2002). However, many students avoid genetics-related questions in Biology at secondary school level, which is the foundation of Senior Secondary School level. Okebukola (2000) also found that,in addition to the above, teachers and students‟ negative attitudes towards genetics teaching and learning play vital role in their poor performances. Umeh (2002) also found that, using lecture method retards meaningful learning of genetics. Genetics is an important component of Biology all over the world and it has attracted many researchers in recent years (Kindfield, 2007). Understanding of genetics does not only mean that knowing how one generation of living organism transfers its traits to the next one and so on, but it is a basic conceptual framework to understand other biological phenomena such as reproduction in living things, evolution and biodiversity (Ayuso, 2003, Chi-Yan &

Treagust, 2003& Mahmud 2009).

Mahmud (2009) in his study observed that students‟ poor academic performance in Biology was as a result of their poor knowledge of genetics taught. The academic performances are also low as a result of non coverage of the syllabus in the area of genetics as well as the use of appropriate teaching strategies which make students hate the topic and the situation leads to poor performance of students in genetic and especially

Biology, at senior secondaryschools. Previous studies like that of Lawal (2005), Umeh (2006), Rotbin (2006), Araz (2007) and Lawal (2010) show that students have difficulties and confusionin learning genetics in which the situation leads to poor performance of students in Biology, especially at senior secondary school, level (WAEC Chief Examiners‟ Report, 2015).

However, there are some opinions among researchers that genetics is quite difficult for students to learn (Johnstone& Mahmoud, 1999). To Banet and Ayuso (2000), genetics is one of the domains that require learners to use multilevel thinking and reasoning involving higher – order thinking. The overview of comparison between teachers and students‟ perception showed that most students thought that, genetics is difficult to learn. According to (Chief Examiner‟sReport, WAEC (2012-2015), students who attempted questions in genetics were not able to link biological concepts to real life situations. Umeh

(2002) also noted that many teachers have phobia for genetics. James (2000) observed that Senior Secondary School teachers also performed poorly when teaching genetics at secondary level, thereby leading to poor performance of secondary school students.

To further buttress the fact that learning of genetics – related concepts has been posing problems to students of Biology, Tsui and Treagust (2002) reported in their study that certain level of knowledge of numeracy as well as analytical ability which is lacking in many students of Biology for proper understanding of genetics is a contributory factor to their poor performance and hence their dislike of the concept. In this study, an attempt will be made to compare two constructivist teaching strategies (problem-solving and discovery strategy) in order to determine their effectiveness or otherwise in teaching genetics in senior secondary school.

Constructivism is a paradigm or ideology which views learning as an active process in which students consciously construct their own knowledge based on the existing knowledge. Constructivism sees students as active participants with knowledge construction and not passive listeners. Several constructivist teaching strategies exist, some of which include; problem-solving, discovery, corporative inquiry among others.

Constructivist teaching strategy of problem-solving and discovery strategiesare used in this study. Problem solving is a strategy to be used in this study. Problem – solving is viewed by researchers from different points of view. Among the researchers that viewed problem-solving were Duke (1999) and Danjuma (2005) who opined that, problem – solving is a request for a certifiable outcome to a situation. They further added that solving problem is a method of organizing information and using that information, along with the knowledge possessed to obtain the desired outcome or solution. Bransford and Stein (2000) viewed problem – solving as the process of moving towards a goal when the path to that goal is uncertain. They added that to solve a problem is to find a way around an obstacle and attain a desired end that is not attainable by appropriate means.Problem solving being an activity based where students learn by themselves through various activities in which students acquire meaningful learning as stated (Bankure, 2012).

Problem – solving teaching strategy is said to have contributed in enhancing students‟ academic performance in science, (Adamu, 2014). In this study, problem solving teaching strategy ofpolya‟s models(Jensen, 1996), was used to find out its effectiveness or otherwise in enhancing students‟ academic performance in genetics at Senior Secondary

School.

Another method of instruction which is activity-basedthat would be deployed in this study is discovery. This method in science teaching was postulated by Bruner (1961). The method enables students to gain experience in using facts, concepts and principles, by using mental processes and manipulating scientific equipment and materials. Bruner believes that a child who is exposed to the heuristics of discovery gets some benefits in learning concepts. Finally, the method is one of the activity – based, as teachers cannot teach science effectively without employing activity – based method.Among others, discovery strategy allows students to actively participate in learning activities and this make students to gain meaningful learning through discoveryof certain concepts on their own (Usman 2000, & James 2000).

This study is necessary becausethe two strategies have different types of approaches.For example, problem-solving strategy allows students to discover certain concepts and also makes ability to solve problems by themselves. Problem-solving

consists of five stages:

1. Introduction: the teacher presents a problem to the students with relevant concept of genetics.
2. Students‟ activities: students are allowed to think and solve the problem presented individually on paper.
3. Discussion: students discuss some similarities and difference of their answer with a partner sitting.
4. Students‟ activities: students share their ideas and findings together.
5. Evaluation: students are asked questions on what they have learned using problemsolving.

While discovery teaching strategy allows students to discover certain concepts but not necessary to solving them, it consists of four stages as follows:

1. Introduction of genetic concepts.
2. Students‟ activities using discovery strategy of students‟ activities on genetic

concepts.

3. Discussion: the teacher asks the students to present their findings from activities carried out and observations made.
4. Evaluation: the teacher evaluates the lesson by asking the students some questions based on what they have discovered by themselves. Based on this, there is need to determine which is more effective in the teaching and learning of gentics at senior secondary school level due to their different strategies and approaches.

Therefore, in this study, discovery teaching method as one of the constructivist teaching strategies was explored and compared to problem solving strategy to find out which of them will improve students‟ performance in genetics, retention ability and

attitude and to determine the strategies have upper hand.

Lecture method, also known as traditional method of instruction, is a method of teaching that emphasizes “talk and chalk” in the teaching of science subjects. More than

80% of scientific information and principles are delivered to students‟ through lectures, (James, 2000). Teachers embrace the method for easy coverage of the school syllabus. It is characterized by one way flow of information and as such, it makes the teacher active, while students are passive. It is one way flow of information which some researchers believe does not promote meaningful learning (Usman & James, 2000). The lecture method will be used as a control teaching method in this study.

Attitude is one of the most important and frequently researched variables in science teaching. Ibraheem (2008) defined attitude as a learners disposition to respond in a consistently favourable or unfavourable manner with respect to a given object. Attitude of students towards science forms an aspect of this study so as to establish the differences (if any) in the attitude of students before and after exposure to two constructivist instructional strategies. Apparently, some studies, Dana (2006) and Adesoji (2008) have been conducted into the area of attitude. Such studies revealed that, students attitude to science is affected by some instructional methods among others. There is need to conduct a study to investigate the effects of constructivist teaching strategies (problem solving, and discovery) on students‟ attitude towards genetic concept. Therefore, the two constructivist teaching strategies wereused with lecture method to see whether they could improve SSS students‟ attitude, retention and academic performance in genetics.

Another variable of this study is the issue of retention ability. Retention is the ability of a learner to recall, remember and recollect a body of knowledge after passing through instruction at a given time duration (Oyetunde, 2000). Permanent and meaningful learning is the ultimate target of our educational endeavour. Understanding and retention are products of meaningful learning when teaching is effective and meaningful to the students (Bichi,2002). Bichi (2002) also observed that retention is the ability to retain and consequently remember things, experienced or learned by an individual at a later time. It takes place when learning is coded into memory. Thus, appropriate coding of information provides the index that may be consulted so that retention takes place without an elaborate search in the memory line. The nature of the materials to be coded contributed to the level of retention. Materials are related to the quality of retention in terms of their meaningfulness, that is when students are able to see what they learn using laboratory strategy and mental processes to carryout activities inform of problems solving.

Muhammad (2011) stresses that anything that aids learning should improve retention while those leading to confusion or misinformation among learning materials decrease the speed and efficacy and accelerate forgetting. In this study, the constructivist teaching strategies wereused with the lecture method as a control to find out if it could improve SSS students‟ retention ability in genetics or not.

Gender is another factor in science education. Bichi (2002) defined gender as the amount of masculinity and femininity found in a person and obviously while there are mixtures of both in most human beings, normally male has a preponderance of masculinity and the normal female has a preponderances of feminity. The concept “gender” has

attracted the attention of many psychologistsand researchers as a result of which a lot of literature exist on different aspect of science education. The influence of gender on students‟ performance has for a long time been a concern to many educational researchers.

But surprisingly no consistent results have been obtained (Francis & Babatunde, 2008). Philips (2006) had opined that girls excel consistently in arithmetic computation and supervision in reading and hand writing, while boys are slightly better in arithmetic reasoning, geography, geometry and history. Usman (2000) observed that if male and female are exposed to activity-teaching strategy such as discovery outdoor and indoor strategies they will perform equally well. What will be the case if problem-solving and discovery strategies are used? The present study, therefore examined the impact of problem-solving and discovery strategies on attitude, retention, and performance in genetics concept to see which of them will improve the gender difference or otherwise.

1.1.1 Theoretical Framework.

The theoretical frame work of this study is based on constructivist Piaget (1967) and Bruner (1961) and Gagne (1970) theories of learning. These constructivist theories of learning have its roots in cognitive psychology, philosophy, learning theory and education theory. Also,constructivist streams from several theories such as information processing theory and Bruner learning theory (1961) suggested that learning can be meaningful by using activity-based instructional strategy such as problem solving, discovery, inquiry, among others. Problem-solving is a set of steps to reach a goal using problem-solving skills. Problem-solving strategyis among the constructivist activities that are activitybased.Inconstructivist learning the role of the teacher is to guide and channel the learning process rather than providing knowledge.

Gagne, (1970) suggests that problem solving can be viewed as a process by which the learner discovers the combination of previously learned rules that can be applied to achieve a solution for a novel situation, in form of hierarchy of knowledge but it is also a process that yields new learning. These are as follows: (a) The learner discovers. (b) Previously learned rules. (c) Achieves solution. (d) Novel situation; and (e) New learning.The processes stated are important to be followed when employing problem solving strategy which is part of the treatment to be administered in this study.  Problem solving as a constructivism teaching strategy was used in this study to determine its effectiveness on students‟ academic performances in genetics. Bruner, (1961) explained that; it is only through the exercise of problem – solving and the effort of discovery that one learns the working heuristic of discovery.

Discovery strategy is another constructivist idea, Piaget (1967) believed that, individuals construct their own knowledge as a result of their interaction with specific phenomenon as in the case of discovery concepts. Such constructed knowledge usually formed the basis upon which new knowledge is anchored and ideas from rote learning to meaningful learning through exploration of the environment by the child are explored. The use of activity – based method of instructions such as discovery method advocated for science educators to help shift the learners from passive to active participation(Kikas, 2004). The method makes use of theories of learning by psychologists such as problemsolving which is one of the strategies of science teaching. Ajewole (2007) observed thatdiscovery is an approach to investigation/inquiry teaching whereby students are guided or assisted in a way in their learning activities so that they can arrive at finding a concept of the subject matter. In this research, the problem-solving theory of Bruner (1961)was adopted as well as discovery strategies of Piaget (1967) in which the impact of problemsolving and discovery strategies on attitude, retention and academic performance in genetics was investigated among SSII students‟ in Zaria.

1.2       Statement of the Problem

The poor performance in Biology has been attributed to so many factors.For example Bichi (2002), Danjuma (2005), Adamu (2014) and Suleiman (2015) observed that activity based instructional strategy such as problem-solving, discovery, inquiry, demonstration could enhance academic performance of students.Since poor academic achievement in genetics according to Okebukola (2000) has been attributed to students‟ poor manipulative skills, insufficient materials, poor teaching strategies and difficult genetic concepts could be as a result of teaching strategy used by Biology teachers. It also record that 70% of the scientific information is passed to students via traditional method, (Bichi, 2002).Most teachers use lecture methods hence the low performance.Lack of problem solving ability. Students‟ perception of genetics concept as a difficult subject, lack of qualified teachers, lack ofteaching facilities, inadequate coverage of syllabus, persistent use of lecture strategy and the complex nature of genetics concepts may be among the factors leading to poor performance. Several studies were carried out using problem-solving and discovery teaching strategysuch as does of Adamu (2014) and

Suleiman (2015);individually in teaching genetic concepts using separate teaching method.Despite the researcher by using problem-solving and discovery strategy students‟ performance in genetics still persist. Therefore is indebted to fill this gap. In line with this, the researcher sought to investigate the impact of problem-solving and discovery strategies on attitude, retention and performance in genetics concept among secondary school students.

A number of studies on teaching strategies have been carried out in genetics at secondary and tertiary levels by several science educators, such as, Ibraheem, (2004) and Lakpini (2006) among others. Genetics is one of the important aspects of Biology curriculum at secondary school level. Students who were taught genetics at the Senior Secondary School level found genetic concepts difficult to understand, thereby leading to their poor academic performance (Wynne, 2001). Also, studies have shown that, students performed poorly in Biology as a result of their poor performance in genetics. However, there are agreements among some researchers that genetics is quite difficult for students to learn (Banet & Ayuso 2000), because it is one of the domains that require learners to use multiple thinking and reasoning that is central to higher order thinking (Chiyan & Treagust, 2003). West African Examination Councils Chief Examiner‟s Report, (2014) reported that, only few candidates attempted questions in genetics and those who attempted genetic questions failed them. The failure of SSS students in genetics as observed by Okebukola (2001) was linked to the way teachers teach genetics at Senior Secondary School level by constant use of lecture method which does not allow students‟ active participation.

From researches conducted, the empirical evidence supports the use of problemsolving and discovery teaching strategy,but most studies were concerned with one experimental teaching strategy without making multiple comparison and indicating which of them is the best.The researcher in this study therefore uses more than one teachingstrategy to findout which one has more impact or otherwise in the teaching of genetic concepts. The persistent poor performance in genetics at Senior Secondary School level therefore, needs to be addressed possibly by using constructivist teaching strategies such as discovery strategy, problem solving which allow active students‟ participation. For this reason, the researcher provided empirical evidence to support the effectiveness of the two teaching strategies on academic performance, attitude, retention in genetic at the Senior Secondary Schools.

1.3       Objectives of the Study

This study has the following objectives, which are to:

1. examine if problem solving and discovery strategieswould enhance academic performance in genetic concepts among SS II Students.
2. investigate whetherproblem solving and discovery strategieswould improve retention ability of SS IIstudents in genetic concepts at senior secodnary school.
3. determine if problem-solving and discovery strategieswould enhance SS II students‟ attitudetowards genetic concepts.
4. investigate whether problem-solving and discovery strategies would have effectson male and female students‟ academic performance in genetics concepts.

1.4        Research Questions

For the purpose of this study, the following research questions were formulated to be answered:

1. What is the difference in the academic performance post test mean scores of SS II students taught genetics concepts using problem-solving and discovery teaching strategies compared to their counterparts taught using lecture method?
2. What are the differences in postpost test mean scores of SS II students taught genetic concepts using problem-solving and discovery teaching strategies compared to their counterparts taught using lecture method?
3. What is the difference in the attitudinal change of senior secondary school SS II students towards genetic concepts when exposed to problem-solving, discovery strategies and those taught with lecture method?
4. What are the differences in academic performance of male and female SS II students in genetic concepts when taught using problem-solving and discovery strategies?

1.5 Null Hypotheses

The following null hypotheses were formulated for testing at P ≤ 0.05.

Ho₁: There is no significant difference in the posttest mean scores of SS II students taught genetic concepts using problem-solving and discovery teaching strategies compared to their counterparts taught using lecture method.

Ho₂: There is no significant difference in the post post test mean scores of SS II students taught genetic concepts using problem solving and discovery teaching strategies compared to their counterparts taught using lecture method.

Ho₃: There is no significant difference in attitudinal change between students taught using problem-solving, discovery and those taught genetics with lecture method at SS II students.

Ho₄: There is no significant difference in the post test means scores among male and female

SS II students taught genetic concepts using problem-solving and discovery            strategies.

             

1.6       Significance of the Study

The findings of this study would hopefully uplift the standard of Biology education in the following ways:

Biology Teachers: The research findings would hopefully benefit Secondary School Biology teachers towards using more effective teaching strategies for effective learning of genetic concepts such as problems solving and discovery teaching strategies.

Biology Students:  It would be of benefit to the students as the findings may lead to an improvement in their academic performance and retention through the use of three consrtructivist strategies of teaching genetics concepts, i.e concept of cell,types of cells in a living organism, function of cell in a living organism, mitosis, meiosis, differences betwen mitosis and meiosis.

Professional Bodies: The findings will be useful to various professional agencies and associations such as Science Teachers‟ Association of Nigeria (STAN), Nigeria, Education Research Development Council (NERDC) and Teachers‟ Registration Council of Nigeria (TRCN) who are concerned with outcomes of research especially in the area of instructional innovation for effective teaching and learning.

Textbooks Publishers: Textbooks Publishers will find this work useful as it will assist in selecting materials and exercises to be incorporated in it, making refrence to constructivist teaching strategies used in this study.

Researchers: The findings will also provide new information to the existing literature in biology education and it will also serve as a foundation for the further similar studies.

1.7       Scope of the Study:

The subjects used for this study were public secondary school students in Zaria

Metropolis Zone, Kaduna State. SS II students were used because the SSI students could not be used because they have just been introduced to genetics in Biology syllabus. While SSIII students are preparing for their SSCE and they may not concentrate effectively on this study consequently, SS II students were be used for the study. The scope of the study comprises of secondary schools which spreads through Zaria Metropolis. The public secondary schools were used for the study.

The concepts taught in genetic have been chosen for the study because the genetics concepts are centred on the biologistunderstanding of a number of aspects of the living system and also has been proved to be difficult for students to understand (West Africa Examinations Council (WAEC) Chief Examiners‟ Report, 2012 & 2015. These concepts

are:

• Types of cellin a living organism.
• Functions of cell in a living organism.
• Meiosis
• Differences between mitosis and meiosis.

1.8        Basic Assumptions

The study has the following basic assumptions put forward for the study:

1. The subjects for the study are familiar with the use of activity – based teaching strategies such as Problem solving and discovery.
2. Biology teachers are familiar with  the teaching of genetics  using appropriate teaching strategies, such as problem-solving and discovery.

EFFECT OF PROBLEM SOLVING AND DISCOVERY POLICIES ON ATTITUDE, RETENTION AND PERFORMANCE IN GENETICS CONCEPTS AMONG SECONDARY SCHOOL STUDENTS IN ZARIA, KADUNA STATE NIGERIA