REVIEW OF THE RELATED LITERATURE
2.1 Meaning of Misconception
A misconception is a belief, view, or opinion, which is incorrect. According to Collins Concise English Dictionary 1988, Misconception means “false or mistaken view, opinion or attitude”. According to Oxford English Dictionary 2011, Misconception means “inaccurate or erroneous conception”.
2.2 Misconceptions in Science; what it is?
Students go to school with different experiences, ideas and explanations of their own which they have gathered from their surrounding environment. The ideas and thoughts are as diverse as the students’ backgrounds. These ideas and thoughts are often original and different from those of scientists. According to many researchers, different perceptions of concepts are mostly formed as a result of students’ daily life experiences. A number of research studies have been done in the area of science education by science education researchers and cognitive psychologists. These studies done in the area in students’ ideas concerning phenomena taught in the science subject and the most common is regarding photosynthesis. In broad terms, misconceptions correspond to the concepts that have peculiar interpretations and meanings in students’ articulations that are not scientifically accurate. In literature, misconceptions are also referred to as naive beliefs (Caramazza, McCloskey & Green, 1981), erroneous ideas (Fisher, 1985), preconceptions (Hashweh, 1988), multiple private versions of science (McClelland, 1984), underlying sources of error (Fisher & Lipson, 1986), personal models of reality (Champagne, Gunstone & Klopfer, 1983), spontaneous reasoning (Viennot, 1979), persistent pitfalls (Meyer, 1987), common sense concepts (Halloun & Hestenes, 1985), spontaneous knowledge (Pines & West, 1986), alternative frameworks (Driver & Easley, 1978), and children science (Gilbert, Watt& Osborne, 1982). Although the term misconception is dominant in the literature, some researchers (e.g., Abimbola, 1988; Gilbert & Swift, 1985; Wandersee, Mintzes & Novak, 1994) now prefer the term alternative conception. These researchers indicate that the later refers to experience-based explanations constructed by a learner to make a range of natural phenomena and objects intelligible. Also, it confers intellectual respect on the learner who holds those ideas (as cited by Bahar, 2003).
The results of research studies show that students come to classrooms with their existing knowledge that they construct with their experiences or formal learning (Fetherstonhaugh & Treagust, 1992; Driver, 1987). Students gather these notions from their surroundings and socializing within and outside the classroom. Thus, students of all ages throughout the world have different notions of science. (Driver et. al., 1994) said that from the personal perspective classrooms are places where individuals are actively engaged with others in attempting to understand and interpret phenomenon for themselves and where social interaction in groups is seen to provide the stimulus of differing perspectives on which individuals can reflect. The gathering of information occurs from their own experience which they come across. The studies have shown that pupils usually develop alternative conceptions a result of their own interpretations or from some contradictory explanations in school or out of school environments in early periods (Wandersee, Mintzes& Novak, 1994).
Students form their own concepts regarding their surroundings and the world. These are based on their own sensorial experiences. Hence, they interpret the world accordingly and it makes sense for them. These interpretations may vary from student to student. Usually, their interpretations are simplistic and are not in agreement with the accepted scientific phenomena. The fact that children tend to develop their own conceptions or preconceptions about certain aspects of the physical world has been known for a long time (Iqbal, 2002). Moreover, (Driver et. al.,1985) mention that children try to interpret prevailing acquired phenomenon with previously acquired ideas. Students bring their own understanding of the subject into the classroom. Their ideas are premature and naive. The reasons may be their upbringing and home environment which is the initial factor to develop misconceptions. Therefore, Driver (1985) also mentions that the possible sources of students’ misconceptions are: school teaching, outside school teaching, everyday experiences, social environment and intuition.
Students’ prior knowledge that they bring to classrooms are called as preconceptions. According to Ausubel (1968), if new concepts were compatible with previous concepts, the meaningful learning would occur. However, some “preconceptions may differ with the established scientific view. These preconceptions which differ or are in conflict with scientific views are called ‘misconceptions’. According to Khurshid & Iqbal (2009), if the students have misconceptions then, they are likely to reject the scientists’ viewpoint and thus, have continued incorrect concepts related to scientific knowledge and views. In literature, the students’ misconceptions have been called with numerous names such as; alternative conceptions (Fisher, 1985), preconceptions (Amandin & Mintzes, 1985; Gallegos, et. al., 1994), alternative frameworks’ (Driver, 1981), erroneous ideas (Sanders, 1993), children’s science (Osborne, et. al., 1982), naïve theories of alternative conception (Trowbridge & Mintzes, 1985), alternative conceptions Gilbert & Watt (as cited in Fetherstonhaugh & Treagust, 1992), as mistakes, errors, misunderstandings, misleading ideas, and misinterpretation of facts Barras (as cited in Odom & Barrow, 1995), private concepts Mintzes (as cited in Odom & Barrow, 1995), naïve conception or naïve knowledge (Reiner, et. al., 2000) and as a common-sense belief (Hestenes, et. al., 1992). Many of the conceptions are scientific misconceptions associated with intuitive ideas or preconceptions Driver (as cited in Odom & Barrow, 1993). According to (Iqbal, 2002) a misconception is an evaluative term that refers to an improper or incorrect conceptual framework.
To sum up, researches around the world indicated that, students hold many ideas, or conceptions which were not in accordance with the way that scientists or researchers understood about the world in which we live. Now we know that these scientifically incorrect conceptions are commonly called by many as; misconceptions, preconceptions, naïve conceptions, alternative conceptions or alternative framework. Thus, misconceptions may also be referred as preconceived notions, non-scientific beliefs, naïve theories, mixed conceptions or erroneous conceptions and conflicting ideas. Students have these premature ideas throughout their lives. According to Iqbal (2002), children’s views and meanings can be quite different to scientists’ meanings. Their understanding differ to science concepts and a cause for misconception in their minds.
Review of the related literature shows that a number of methods and techniques have been used to identify students’ misconception in science area. Most of the methods were used by administrating a variety of pen-and-pencil instruments, (Marmaroti & Galanopoulou, 2006). While many used two-tier diagnostic tests to identify students’ misconceptions (Haslam&Treagust,1987; Odom & Barrow, 1995; Ozkam, 2001), while other used true/false type questions (Mann & Treagust 1998) and concept evaluation statement (Simpson & Mariek, 1988; Westbrook & Marek, 1991) as cited in (Tekkaya, 2002). And, also drawings have been considered as simple research instruments Kose (2008), while others such as (Tamir 1971), (Doran 1972), (Linke & Venz, 1978, 1979) and (Hallous & Hestenes, 1985) have used multiple-choice test to diagnose students’ misconceptions in science (as cited in Haslam & Treagust, 1987). Very effective and unique way to explore misconceptions in students’ is by concept cartoon. (Ekici, 2007) have also used this method. Different cartoons are drawn to isolate the misconception. According to Chin (2001) concept cartoons make use of cartoons characters engaged in dialogue and integrate text in dialogue form with a visual stimulus. Interview techniques have been in, for a very long time to isolate students’ misconception very deeply and intensely worldwide. Interview is a widespread technique used to identify students’ misconceptions on a particular topic (Fisher, 1985; Ozkan, 2001; Sungur, et. al., 2001) (as cited in Tekkaya, 2002). Interviews help to detect any misconceptions related to any particular topic. It can help to read the minds for some specific topic. According to (Tekkaya, 2002) the purpose of interview is to tease out the students’ meaningful understanding of a particular concepts. Also, according to (Osborne & Gilbert, 1979), critical aspect of students’ understandings could be explored. So, interviews are useful technique in obtaining misconceptions on specific science concepts. (Osborne & Gilbert, 1980) and (Watts, 1981) have described a variety of interview technique, according to them Interview-About-Instances and Interview-About- Events are very constructive methods to probe scientific misconceptions of students. Both these are effective means to see what the students think and has concept for the subject. The subject knowledge can be tested with all sides and angles related to that topic. Interview-about-instance show situations which include instances and non-instances of a concept. Furthermore, (Mitchell & Gunstone, 1984) have used an interview format which is a mixture of these procedures (as cited in Treagust & Haslam, 1986). However, in most of these studies the administered instrument was open-ended. These studies were followed by others which correlated the findings and thus the matter progressed as study strategies (Hazel & Prosser, 1994). Although, researchers gain more information by increased depth of probing and enhanced flexibility of questioning in interviews Beichner, 1994 (as cited by Kutluay, 2005) they require a large amount of time to interview with students but it gives intensive knowledge regarding the topic. It is the most effective means of probing the students ‘thought’ or ‘ideas’ about a particular topic. The method is taken by many researchers prefer this technique to read the minds of the students. Thus, many researchers have found misconceptions prevailing in the minds of students which are hard to remove. The concepts are not materials, events or creatures but they are units of thought assembled into certain groups (Cepni, Tas & Kose, 2006).
2.3 Nature of Misconceptions
Literal meaning of misconception is a mistaken notion. Misconception, false opinion, wrong and premature understanding exist in all age groups of students as well as people throughout the globe. Misconceptions are what students themselves develop erroneously and are different from scientifically accepted concept (Kose, 2008). These misconceptions, also known as naïve or alternative conceptions are prone to be extremely resilient to any change. These are quite strongly embedded. These misconceptions are believed to have a nature, to become the part of cognitive structure. Misconceptions have often been incorporated securely into cognitive structure Ausubel 1986; Driver & Easley, 1978; Gunstone et. al., 1981 (as cited in Treagust, 1988). Moreover, these are difficult to dissociate or modify easily as these are accumulated over a long period of time. The students’ experiences from daily life usually impedes to change the misconception easily. These are intensive and resistant to change, until suitable teaching strategies are applied. Much effort is being done in this direction to limit the misconceptions in students. These misconceptions are at odds and in disagreement and conflicting with the contemporary scientific views and ideas. Research reveals that misconception is hard to eliminate through traditional approaches because it is a permanent and continuous process, and it is not sufficient to develop right concepts on students (Tekkaya et al., 2000). Misconceptions or preconceptions or alternative conceptions connote cognitive structures, as opposed to events or patterns of behaviour that are inconsistent with scientists’ cognitive structure. They interfere with rather than contribute to students’ development expertise (Hammer, 1996). Moreover, misconceptions are resistant to change. Thus, they interfere with learning process and inhibit the learning in students (Kutluay, 2005). In the fear of failing in examination, students rote learn the scientific and non- scientific concepts with their target being only to clear the examination. According to (Kutlualy, 2005) although they are able to pass almost any exam through the memorization of basic problem skills, they do not understand the principle involved in the solution of the problems.
Hence, misconceptions have a detrimental nature that restrain and hampers in learning of students. Thus, hinder in the learning of scientific facts. Students are unable to remove their misconceptions and over the years these become permanent in their mind and become the part of their knowledge. These misconceptions work as stoppers to acquire new ideas or fact given by the teacher and therefore, students find themselves in confusion and thus disagree with the scientific concept.
2.4 Misconceptions in students; what are the common sources?
All students when they enter into science classroom bring some misconceptions with them because of a variety of their experiences. Many of these misconceptions are related to their own instinctive ideas or preconceptions developed prior to joining their school (Driver, 1987). Several investigative research studies have revealed that there are many sources of misconceptions which exist in students. For example, student’s everyday life experiences, use of words and certain terms in non-scientific context causes confusion in students. Translation of scientific word or concepts during the explanation of lessons leads to misconceptions. Translating the concept or giving daily life experience to students in class also erupts to confusion. Plus, scientific terms are constantly changing with current knowledge. Scientific terms that are used in different contexts because they have shifted their meaning in the course of the historical development, Schmidt, 1997 (as cited in Dikmenli, et. al., 2009). Misconceptions also arise due to common use of scientific terminology in day to day language, in other words exploiting the scientific concept. Another source is the combination of a newly learnt concept with the previously held concept, may resort to disagreement in students’ mind. Teachers transfer misconceptions to their students in classrooms. The reason is that either their own concept is not clear or they were unable to explain properly. According to (Tekkaya, 2002) misconceptions passed from teachers to students through wrong or inaccurate teaching. Since the concept is not clear in the teachers’ mind therefore the making of assessment may mislead the students. Thus, the method of examinations and tests (Sanders, 1993) through assessment strategies are also a cause. The textbooks and the relevant teaching-learning material which is available to teachers is written in much complex way, that the teacher who does not have a strong scientific background fails to grasp it completely. The teaching material provided to teachers is of higher educational standards and complex. The teachers are unable to comprehend fully and thus the confusion is translated in the teaching. The teacher guide is also a cause which creates misconception in teachers. This should be drafted with clarity. The teacher’s guides do not especially address what are the most common misconceptions and the text is probably too complex for teachers with limited scientific background to fully understand. Students develop certain misconceptions since science is being taught as a historical account. Demonstrations, observation and experimentation find a little space in teaching of science. The content teaching is not supported with practical experimentation (Khurshid& Iqbal,2009). Generally, science textbooks are the source of misconceptions in pupils as well as teachers. According to (Saleem, 2001) there are several sources from which misconceptions emerge, but some common and important sources with reference to textbook misconceptions are as follows:
- Presence of error in textbooks. Students’ ideas do not always evolve as quickly as the rate of concept presentation in most textbooks and in many teacher-designed units of instruction.
- High degree of difficulty of language used in textbooks meaning language used by teachers and textbooks may confuse some students to a great extent.
- Confusing presentation of a concept. Instruction which fails to identify what students’ initial ideas are can leave students’ erroneous ideas unchanged.
- Presentation of concept by the teacher in such a way that encourages a misconception. Some ideas are just too abstract and difficult for many students who are still at a concrete learning stage for examples; empty space between atoms and molecules.
- Teachers and the tests given to the students, often, assume that students understand a concept based on the words students use when describing something (e.g.: evaporation). Scientific terminology is not sufficient evidence of learning unless you can ensure that students use the terms with meaning.
- Presence of incomplete diagrams, pictures, diagrams and2-dimensional models in textbooks and other instructional materials can be misleading, which results in misconceptions.
- Mistake made by editors during editing.
- Misconception of author about certain topics in the concept.
- Some common analogies used to explain ideas can cause difficulty because the similarity is not complete.
- Demonstrations used by teachers are often passive where students sit back and observe without manipulating materials or experiencing the phenomenon individually or in small groups.
- Misconceptions can arise from differences between common uses of terms and their scientific use (Odom & Barrow,1993). Everyday use of certain terms, often used in nonscientific contexts, contributes to students’ confusion. Some words have many different connotations in the English language and the scientific word can easily be confused with a common use, a very common example is of heat rises and heat is given out.
Curriculum, instruction, and assessment are significantly the factor contributing towards student’s misconceptions in science education. Hershey (2004, 2005) stated that any alternative conceptions existing in a textbook, article or curriculum program may mislead many teachers and students. Misconceptions in the literature, such as, textbooks, have been shown as a strong source of misconceptions for students and their teachers, identified by a range of different problems, such as, oversimplifications, over generalizations, lack of clarity about central concepts, and incorrect diagrams and analogies (Güler & Yağbsan, 2008; Hershey, 2004). Dikmenli and Cardak (2004) have determined 14 alternative conceptions and 10 inadequate knowledge about cell structure and functions in high school first year class biology textbooks that may lead to alternative conceptions (as citied in Dikmenli, et. al., 2009). Leaving misconceptions unchallenged seriously (Galvin, Mooney &Grady, 2015) may lead to misconceptions or alternative conceptions in students at all grade levels. Textbooks which include many errors and in correct information Storey, 1991; 1992 (as cited in Tekkaya, 2002). Science textbooks are among commonly used effective teaching materials in science education process that it seems a significant source of conceptual problems have been detected on pupils (Dikmenli, et. al., 2009). Moreover, pictures, diagrams, figures and strained drawn concept maps can be misleading. Common analogies used in explaining the ideas to students. Memorization and rote learning, is another factor to add students’ misconceptions. According to (Cepni, et. al., 2006) they usually memorize the science concept without understanding the real meaning. It is shown by many studies that, inter-related concepts in science education lead to misconceptions. (Khurshid & Iqbal, 2009) students are unable to discriminate among closely related concepts causing them to mislabel or classify. Pupils daily life experiences and experiments in school laboratories, negates their conceptual learning abilities. According to (Kutluay, 2005), their experiences and the experiments are in conflict. Misconceptions may also arise due to media and internet resources, cultural and traditional beliefs, and (Kutluay, 2005) metaphors ingrained in language. Usually language is a big factor for those who are thought science in a second language. Many students develop misconceptions when their teachers translate in their mother tongue which may not be accurate, thus misconception occurs. According to (Klammer, 1998) the sources of the misconceptions are experiences, language and a curriculum of ‘truths’. Beliefs resulting from personal experience, intuition, and common- sense logic lead students to form their own ideas and erroneous notions. Some students will fail to learn ideas because the subject matter material may be at a level that does not match the developmental learning stage of the student, imposing may produce misconceptions. All the above sources of misconceptions impede cognitive learning in students. These obstruct and frustrate the learner to build association with inter-related concepts in science topics. Biology misconceptions have been recognized as a major factor affecting students’ understanding of science at secondary school level with many misconceptions carried onwards to university studies Coll & Treagust, 2003(as cited in Galvin, Mooney and Grady, 2015).
2.5 The topic ‘Photosynthesis’
Photosynthesis is the synthesis of glucose from carbon dioxide and water in the presence of sunlight and chlorophyll, with oxygen as a by-product. According to Schraer and Stoltze, 1990 photosynthesis refers to the process in which the organic matters are synthesized from inorganic sources by using the energy of light (as cited in Cepni et. al., 1994). Photosynthesis is anabolic (building) process and is an important component of bioenergetics in the living system. In fact, it is the most important biochemical reactions that occur in plants, some protists (algae) and some bacteria but do not occur in fungi.
2.5.1 Chemical Equation of Photosynthesis
6CO2 + 12H2O C6H12O6 + 6O2+ 6H2O
Thus, in Photosynthesis, the active energy of light is transformed and stored in the carbohydrate molecules. The first stable form of carbohydrate formed during Photosynthesis is glucose. It has been found that all oxygen evolved in Photosynthesis comes from water, to form one glucose molecule, twelve molecules of water are split to yield six molecules of oxygen and twenty-four atoms of hydrogen. The hydrogen is used to reduce six molecules of carbon dioxide to form one molecule of glucose and six molecules of water. The actual process is much more complicated than that represented by the above equation. Many intermediate steps are involved before glucose is formed which entirely depends on enzymes.
2.5.2 Explanation and aspects of Photosynthesis
Photosynthesis is a process wherein light energy is trapped by chlorophyll and converted into chemical energy which is then utilized to manufacture organic carbohydrates from inorganic carbon dioxide and water. In this process oxygen is released, as a by-product, to the environment. Photosynthesis is a biochemical process in which the energy of sunlight is used to convert carbon dioxide (CO2) into organic molecules, (Ray & Beardsley, 2008).
Photosynthesis can be represented in a simple general equation as:
6CO2 + 12 H2O + Light Energy C6H12O6+ 6O2 + 6H2O
Water and carbon dioxide are the essential raw materials of photosynthesis. Plants have the necessary mechanisms for the intake and transport of these raw materials
2.5.3 In-take of water and carbon dioxide
Water and carbon dioxide are the raw materials of Photosynthesis. Plants have mechanisms for the intake and transport of these raw materials. Water, present in soil, is absorbed by roots and roots hairs through osmosis. This water eventually transported to leaves through xylem vessels through capillary action and active transport.
Carbon dioxide is present in air about 0.03 percent. This air enters leaf through tiny pores called stomata and reaches the air spaces present around mesophyll cells. The carbon dioxide from air gets absorbed in the thin layer of water surrounding the mesophyll cells. From here the carbon dioxide diffuses into the mesophyll cells themselves.
2.5.4 Role of Chlorophyll and Light
Sun light energy is absorbed primarily by a photosynthetic pigment called chlorophyll. It is then converted into chemical energy, which drives the Photosynthetic process. The light rays of different wavelengths are differently absorbed. The blue and red lights carry out more Photosynthesis.
2.5.5 Physiology of green leaf to understand Photosynthesis
The ability to produce food in plants is credited to the presence of chlorophyll and chloroplast in the leaves.
Chloroplasts are one of the many different types of organelles in the plant cell. The chloroplast is enclosed by a membrane. Within the membrane there is an aqueous fluid called the stoma. The stoma contains stacks (grana) of thylakoids. These are flattened disks bounded by a membrane containing the pigment, chlorophyll.
Pigments are the material which absorb visible light. The nature of each pigment is different. Hence each absorbs light of a different wavelength. Each wavelength determines a different colour. Photosynthetic pigments are organized in the form of clusters, called photosystems, in thylakoid membranes of chloroplasts. Chlorophyll-a is the main photosynthetic pigment which absorb blue and red light effectively. Hence its color is green.
Other pigments are chromoplasts, present in petals of flower and ripe fruit and leucoplast are present in the plant parts where it stores food particularly in roots and tubers etc.
Mesophyll consists of the layers of tissue between the epidermis of leaves. There are two main types of Mesophyll layers. The top layer consists of the palisade cells and under them is the layer of spongy cells. Palisades contain the most chloroplasts. They are closely packed resulting in more chloroplasts to be near the surface of the leaf. There are small spaces between the palisade cells which allows gaseous exchange to occur. Located below the palisade cells is the layer of spongy-cells. These have lesser chloroplasts and larger intercellular spaces. These spaces store the carbohydrates made by photosynthesis. From here the dissolved carbohydrates diffuse into the phloem to be transported to the rest of the plant.
2.5.7 Photosynthesis and Respiration
The process of Photosynthesis is one of the main reasons for continued life form on Earth. The food prepared by the plants during Photosynthesis is used by animals and human beings as food. Oxygen gas released as a by-product during Photosynthesis is used by animals for respiration and carbon dioxide expelled out during respiration is used by plants in Photosynthesis. Therefore, the cycle of Photosynthesis and respiration maintains the balance of carbon dioxide and oxygen on the earth, as both gases are important to support life.
In plants, during daytime both the processes of photosynthesis and respiration go on simultaneously, therefore, carbon dioxide released during respiration is used to make food by Photosynthesis and oxygen released during photosynthesis is used in respiration by plants. Rate of Photosynthesis is higher during daytime as compared to respiration and it stops at night, whereas respiration continues during day and night. Thus, it is advised not to sleep under the plants as these give off carbon dioxide.
A comparison to highlight the differences between Photosynthesis and Respiration is given in the following Table 2.1 for clarity.
Table 2.1 Comparison of Photosynthesis and Respiration in Plants
|1||Photosynthesis is a process in which plants use sunlight to make food.||Respiration is a process which converts the food made through photosynthesis into energy used by plants and other living organisms.|
|2||Photosynthesis takes place inside the chloroplasts. These are organelles inside the plant cells that contain chlorophyll.||Respiration takes place inside the mitochondria and chloroplast. These are organelles capable of breaking down glucose.|
|3||Photosynthesis requires energy to produce glucose. This is an Anabolic reaction.||Cellular respiration uses the glucose to create energy (ATP). This is a Catabolic reaction.|
|4||Photosynthesis takes carbon dioxide, water and sunlight from the atmosphere to create sugar and releases oxygen back into the air.||Respiration combines sugar with oxygen and releases the energy as ATP along with carbon dioxide and water as by-products.|
|5||Photosynthesis occurs in plants, algae and some bacteria.||Respiration occurs in all living organisms.|
|6||Photosynthesis occurs in daytime only as it requires the presence of sun light.||Respiration occurs all the time, that is throughout the day and night.|
In short, green plants are not only important to animals but also maintains the ecosystem of the world. They balance the composition of oxygen in the air and can be considered the ‘lungs’ for the environment and ‘factory’ for food production for all the organisms. (Tal, 2005) explains that importunate misconceptions have been affixed in dynamic knowledge that is functional in a particular context. The verity that from a scientific point of view, it is false and has no implications in the real, everyday life. Problems only result if these concepts are used in contexts in which they are not functional (as cited in Anjum Naz, 2008).
The concept regarding the relationship of photosynthesis and light stands for an importunate misconception that is both an uncomplicated photosynthesis and incidence of light is more comprehensible for students in a day after day context, so it did not change even subsequent to the investigative activities for students.
2.6 Photosynthesis and Students’ Misconceptions
2.6.1 Previous Researches
Secondary school students find photosynthesis conceptually challenging and different researches indicate the same. Understanding photosynthesis, respiration and energy issues in organisms are keys to understanding global issues such as energy flow, food supplies, and other ecological principles, but these are hard subjects that most students have contradicting knowledge about (Ozay & Oztas, 2003).The topic photosynthesis is vital as it is related to primary producers for food source, both for humans and animals. It also helps the students to appreciate that plants are the main source of food for humans as well as other valuable substances obtain by green plants, but unfortunately many misconceptions about photosynthesis are present in students. (Anderson, Sheldon & DuBay, 1990) demonstrated that most students of all ages exhibit strikingly similar misconceptions about photosynthesis. Investigations suggest that although children do not have prior knowledge directly relating to photosynthesis, the purpose many separate, but relevant, views about plant activities and materials. They ascribe varieties of functions to leaves and roots, such as absorbing water, taking materials and capturing sunshine (Ozay & Oztas, 2003). Research pupils’ prior knowledge significantly influences classroom teaching and learning (Lumpe & Staver, 1995). Despite photosynthesis being the production process of green plants, the concept of the process providing ‘nourishment’ for plants contradicts students’ previous ideas of ‘nourishment’ being a solid or liquid substance take from the outside into plants (Ozay & Oztas, 2003). It has been shown that pupils’ have some difficulties understanding that plants manufacture the organic substances forming chlorophyll from the inorganic substances taken from their external environments (Eisen & Stavy, 1993). According to (Cepni et. al., 2006) it has been reported that the “photosynthesis” is one of the most important abstract concepts being difficult in teaching and learning at all levels of schooling (Bahar, Johnstone & Hansell, 1999; Lawson & Thompson, 1988; Storey,1989).
According to (Marmaroti and Galanoupolou, 2006), photosynthesis is an important biochemical process by which energy-rich organic nutrients, for both the photosynthetic organisms and the heterotrophs, are produced from simple inorganic molecules found in the environment. Due to its scientific importance, photosynthesis is considered one of the main topics in school biology and it is included in almost every middle school syllabus. Basic understanding of photosynthesis is necessary to comprehend how the world functions as an ecosystem (Eisen & Stavy, 1988; Stavy, Eisen, & Yaakobi, 1987) and of how it acts as a bridge between the non-living and the living world (Waheed & Lucas, 1992). According to Arnon, “Photosynthesis eminently merits its distinction as the most important biochemical process on earth” (Barker & Carr, 1989).
The topic of Photosynthesis is an essential part of biology curriculum at secondary school level. According to (Waheed & Lucas, 1992), photosynthesis is one of the most important concepts in school biology and it is included in school syllabuses directly under the heading ‘Nutrition in Plants’ and again in biology mainstream courses in college and universities. Being one of the basic concepts in biology, photosynthesis is traditionally taught under more than one subject within the area of biology such as botany, plant physiology, cell biology, ecology and others. Indeed, the topic of photosynthesis is complicated and knowledge in chemistry and physics is also essential to have full understanding of the phenomena which is occurring in green plants. Hence, according to (Tekkaya, 2002), many topics of biology in which students hold misconceptions are basic and have interrelated concepts. Within the studies in biology, photosynthesis is a difficult and complex topic for secondary school students to fully comprehend (Stavy et al., 1987, Waheed & Lucas 1992).
2.6.2 Misconception and inter-relatedness concept in Photosynthesis
Photosynthesis is considered as a difficult and an intricate topic comprising of different conceptual aspects. Literature supports that misconceptions about photosynthesis is more prevalent in students at all levels since as it is unique and tricky to comprehend. In fact, it is a global phenomenon.
Educational researchers have found that many students have misconceptions related to science education particularly in biology. Within the studies in biology, photosynthesis is a difficult and complex topic for secondary school students to fully comprehend. This topic relates to different aspects of prior knowledge and concept in the areas of physics, chemistry, physiology, botany, etc.
Biology as a subject is more interrelated compared to other science subjects. According to (Cibiket, et al., 2008) biology is more interrelated science field with respect to concepts that it covers compared to other science fields. Therefore, students have many alternative concepts. The most evident example of this can be seen in photosynthesis and plants’ respiration (Cibik, Diken & Darcin, 2008). Especially in studies that were performed on Photosynthesis and Plants’ Respiration, subjects of study reveal that misconceptions are very frequent (Haslam & Treagust 1987; Tamir, 1989; Anderson et al., 1990; Amir &Tamir, 1994; Pedro, 1997; Cakici, 1998; Mikkila – Erdmann, 2001; Yuruk & Cakir, 2000; Alparslan, 2002; Tekkaya & Balci, 2003; Cepni et al., 2006; Kose et, al., 2006; Kose & Usak, 2006). In fact, these studies revealed that the majority of students leave secondary school with a distorted view of biological objects and events. Many of these topics about which students hold misconceptions are basics to biology knowledge and interrelated.
Photosynthesis is understood in many different ways. A commonly held (Aristotelian) idea is that plant get their ‘food’ from the soil Wandersee, 1983, Roth & Anderson 1987, Barker &Carr 1989a, b, Wood 1991, Waheed& Lucas 1992, Hellde´n 1998, 1999 (as cited in Carlsson, 2002). Misconceptions about photosynthesis are very common among students of all levels (Bell 1985; Eisen & Stavy 1988; Driver et al. 1994;Yenilmez&Tekkaya 2006). A variety of research approaches has sought to illuminate students’ alternative conceptions about photosynthesis (Griffard & Wandersee, 2001). In fact, from the earlier research, one can say that the misconceptions about photosynthesis exist almost in every biology student.
Waheed & Lucas, (1992) emphasize that it is a complex biological topic and has a number of conceptual aspect namely ecological, biochemical, anatomical-physiological and energy change. Therefore, the interrelationship of the various aspects make photosynthesis an integrated concept, which becomes quite complex for the students. Misunderstanding and misconceptions have been recorded for each of these aspects (Marmaroti & Galanopoulou, 2006). There is also a significant misconception of confusion of photosynthesis with respiration (Amir &Tamir, 1994). Hence misconception concerning the process of respiration as well as its relationship to photosynthesis, and confusion of photosynthesis with respiration has been revealed (Amir &Tamir, 1994; Stavy et. al., 1987) as cited in Marmaroti and Galanopoulou, 2006. The most common misconceptions which very common among the students from all grade level is photosynthesis and respiration. (Tekkaya & Balcı, 2003), carried out a study that aimed to determine the misconception of high school students on the concept of photosynthesis and respiration in plants. These researchers observed that most of the students had the idea that “photosynthesis is a gas alternation process, energy is produced after photosynthesis and photosynthesis is the reverse of respiration” which is not true scientifically at all. Another commonly held misconception is that photosynthesis takes place during the day, whereas respiration takes place only at night. Certainly, there is more emphasis given to the process of photosynthesis and the fact that it takes place during daylight in comparison to when respiration occurs in plants (Wandersee, Mintzes, & Novak, 1994). Cellular respiration is a continuous process in all organisms. The emphasis on the process of photosynthesis must have resulted in the misconception that cellular respiration occurs only at night in plants. Research has revealed that a number of prevalent misconceptions about photosynthesis, such as: plants get food from the soi1, water and minerals taken in from the soil are sources of the plant’s “food”, photosynthesis is the respiration of plants and photosynthesis takes place during the day whereas respiration takes place only at night (Galvin, Mooney & Grady, 2015). Majority of the students have misconceptions regarding respiration in plants that they have learnt. One indicator of level of students’ misunderstandings about plant respiration is that a large number of them still naïvely accept (Canal,1999) that it is same as in animals.
According to research report (Marmaroti & Galanopoulou, 2006), “The most common misunderstanding is the one referred to the autotrophic feeding of plants: a commonly held idea is that plants obtain their food from the soil (Barker & Carr, 1989; Bell, 1985;Eisen&Stavy, 1988; Roth, Smith, & Anderson, 1983; Wandersee, 1983; Wood-Robinson, 1991)”. In many research studies it is mentioned that students have misconceptions regarding photosynthesis that it takes place during the day whereas respiration takes place only at night and in plants. According to them, the plants photosynthesize during the day and conduct cellular respiration only at night. They however, think that cellular respiration is a continuous process. Similar misconceptions are also found among college students (Wandersee, 1983).
Most common misconception that has been revealed by researches is that students have misconception relation to photosynthesis and respiration. They have naïve understanding that photosynthesis is plant related while respiration is animal phenomena. There are also misconceptions concerning the process of respiration as well as its relationship to photosynthesis, and also confusion of photosynthesis with respiration has been revealed. On the other hand, some students understand respiration as synonymous with breathing (Haslam & Treagust, 1987). While many students understand plant respiration as an inverse gaseous exchange compared with that of animal. Again, it is not a scientific fact. The results of the study highlight the consistency of students’ misconceptions across secondary year levels and indicate that a high percentage of secondary students do not comprehend the nature and function of respiration and have little understanding of the relationship between photosynthesis and respiration in plants, (Haslam & Treagust,1987). In short, the process of respiration in general, and in plants particularly, is unknown to a majority of students, Leach 1995, Leach et al. 1995, 1996a, b, Hellde´n1998, 1999 (as cited in Carlsson, 2002). According to Galvin, Mooney &Grady (2015), the word ‘respiration’ is commonly used in everyday language. Students are often taught that lungs are part of the respiratory system, which may contribute to the development of this misconception in the first instance (Deshmukh & Deshmukh, 2007). Terms like “respiratory system”, “respiratory organ”, in which the term “respiratory” needs to be replaced with “breathing”, are commonly used in text-books and by teachers. Another strongly held misconception, held by both students and teachers alike, is that “respiration only occurs in animals and not plants”. This is partly due to some authors defining terms like respiration almost exclusively for animals (Songer & Mintzes, 1994). In fact, students also do not understand processes of photosynthesis and respiration in plants well (Kose, 2008)
As for the energy aspect, many students listed energy as among the materials absorbed by plants. Furthermore, the students have difficulties in understanding the concept of harnessing the sun’s energy during photosynthesis, since very few of them are able to describe the energy transfer occurring during photosynthetic process and very few understand energy transformations (Waheed & Lucas, 1992). There are also misconceptions related to the prerequisite concepts of photosynthesis such as gas, energy conversions, and chemical change (Barker & Carr, 1989;Simpson & Arnold, 1982).
According to (Marmaroti & Galanopoulou, 2006) the concept of energy and its transformations seems very hard for the students to grasp, (Carlsson, 2002a) as they consider that energy is consumed and thus depleted when utilized (Carlsson, 2002b). A chemistry related concept in which, most of the students are unable to understand why the properties of a compound are different from the properties of the elements that constitute it. According to (Arnold and Simpson, 1980), they cannot understand how an element (carbon, which, in pure state, is a solid) can exist in carbon dioxide (which is a colourless gas of the atmosphere). The students have also difficulties in combining chemical and biological concepts (e.g., they cannot treat human body as a chemical system). Therefore, students consider photosynthesis totally a different thing. And thus, fail to comprehend the concept of energy conversion and certain biochemical reaction in which conversion occurs. The main reasons for those misconceptions are students’ previous knowledge, the difference of scientific jargon and daily speeches and course textbooks Kose and Usak (2006).
Throughout the world researchers are trying to find misconceptions in students for photosynthesis, since it involves many aspects. They have devised many methodologies to pin point the alternative concept in student. The misconceptions related to variety of pen-and-pencil instruments (Treagust & Haslam, 1987; Tuysuz,2009). However, the instruments used in these primary reports have studied the understanding revealed by studying documents and by administrating one or two of the conceptual aspects of photosynthesis. Only in a few cases was the understanding of more than two aspects studied (Waheed & Lucas, 1992). According to Marmaroti & Galanopoulou, (2006), “only in Waheed and Lucas study was the interrelationship between these aspects simultaneously investigated. However, understanding of photosynthesis means understanding of all different aspects of the process”, (Driver et. al., 1984), who included an investigation of the relationship between respiration and photosynthesis, linking biochemical and physiological aspects. According to Bell (1985), students’ difficulties in understanding photosynthesis are due mainly to their alternative ideas concerning these basic concepts. The reason for photosynthesis topic being difficult is that, it has different conceptual aspects which need to be fully comprehended prior to its full understanding. Since this topic is included in secondary education, is considered important to be understood by the students. Therefore, a need is there to investigate misconceptions regarding photosynthesis and its aspects. According to (Amir & Tamir, 1993) the importance of photosynthesis and the complexity of the process have made it an excellent candidate for research on students’ conceptions.
According to Marmaroti & Galanopoulou (2006), the main body of the studies of misconceptions was performed during the 1980s. The misconceptions related to photosynthesis have been revealed by studying documents like textbooks (Barrass, 1984; Storey, 1989) and by administrating a variety of pen-and-pencil instruments (as cited in Marmaroti & Galanopoulou, 2006). However, in most of these studies the administered instrument was open-ended. These studies were followed by others which correlated the findings and thus the matter progressed as study strategies (Hazel & Prosser, 1994). Waheed & Lucas, (1992) study the interrelationship between different aspects of photosynthesis and these were simultaneously investigated. However, understanding of photosynthesis means understanding of all different aspects of the process, and hence the need to develop a questionnaire on all these aspects simultaneously (Marmaroti & Galanopoulou, 2006). These researches have isolated many alternative misconceptions among the students. Most researchers took different means to identify various misconceptions related to photosynthesis and its various aspects. According to Marmaroti & Galanopoulou, (2006), there are two usual means for obtaining information on students’ misconceptions and misunderstanding using a pen-and-pencil instrument. In fact, these kinds of tests have led many underlying misconceptions identified.
According to Marmaroti & Galanopoulou, (2006), there are two usual means for obtaining information on students’ misconceptions and misunderstanding using a pen-and-pencil instrument. In paper-pencil multiple choice questions if we add reasoning in selecting the responses then it would provide an improved and relatively straightforward method for identifying the misconception. (Haslam & Treagust,1987). Interview-About- Instances and Interview-About-Events is also a successful technique to diagnose misconceptions in students and teachers. It is widely recommended technique.