Understanding of Photosynthesis By Swetha Manjunath Introduction The concept is Photosynthesis and the learners are between class-3 to class-5(age 8 to 10 years old). Photosynthesis is a process where plants and some organisms through the use of sunlight, carbon dioxide and, water produce glucose which is essential to grow and thrive and release oxygen into the ecosphere. “Photosynthesis is a series of processes in which electromagnetic energy is converted to chemical energy used for biosynthesis of organic cell materials; a photosynthetic organism is one in which a major fraction of the energy required for cellular syntheses is supplied by light.”(Gest,1993). photosynthesis is very important for our learners because of our quality of life and indeed the existence of life on planet earth depends on it.it prevents environmental and ecological disasters. By learning this we can enhance food production and energy. It also helps use the basics chemistry and physics of photosynthesis in other fields. It is crucial to understanding how carbon-di-oxide and other gases affect the global climate. Photosynthesis is a natural action and therefore the impact that it has on all of our lives. One can control photosynthesis by doing proper research of photosynthesis, and apply its principles for the betterment of mankind” (Gust,1996) Students will have an erroneous understanding of the concept is called misconceptions. Below are the misconceptions about the photosynthesis concept for students aged between 8 and 10 years old. photosynthesis is the respiration of plants carbon dioxide is food for plants Sunlight is food for plants The food for plants is water and various minerals from the soil Carbon-di-oxide as mandatory source energy for photosynthesis carbon dioxide is converted into oxygen during photosynthesis the Major photosynthetic product from photosynthesis is glucose Photosynthesis occurs in the light and respiration in the dark. the sunlight is converted into food during photosynthesis. Plants do not use oxygen Plants do not do respiration Due to misconceptions, students use these wrong understandings to interpret new experiences, this will impact the grasping of new experience. Students are generally unaware they have understood wrong, it will affect student's thinking. students often believe that plants perform “reverse breathing” during which they inhale carbon di oxide and exhale oxygen. plants use and produce both carbon di oxide and oxygen through two processes: photosynthesis and respiration (Jessica FriesGaither,2009).The lower secondary students have common misconceptions about concepts of photosynthesis and plant respiration. Many students tend to misunderstand the concept that photosynthesis and plant respiration are not related even though it is a mutually connected physiological function. Many mistakes photosynthesis for respiration in plants and that respiration took place only in leaves that have special organs known as pores. They also believed that the plant produced oxygen over the whole day which the foremost important source of food for plants is water with dissolved mineral substances. teachers can eliminate misconceptions by the proper explanation of these concepts, correct chemical clarification of photosynthesis and respiration, and connecting integration about these processes (Katerina Svandova,2013) Conclusion Photosynthesis is an important process in the ecosystem because it is a primary source of food and oxygen. No Life exists without photosynthesis. It is required to be learned by all the students to learn the basic understanding of how the world functions as an eco-system and remove all the misconceptions on photosynthesis. Through the understanding of photosynthesis, we can do more research in improving food production. by understanding the physics and chemistry involved in photosynthesis solar energy conversion, design on electronic circuits, development of medicine, and drugs. Helps in reducing pollution and climate control. It is also required to do more research on photosynthesis and make the planet a hospitable environment. Photosynthesis is a very important concept to learn. Without understanding the process of photosynthesis, life on earth would be very difficult to understand, there are many things yet to be explored in the field and nevertheless, much research is still going on. Works from researchers about the importance of this concept in educating children. Teaching photosynthesis is compulsory in school context will encourage students to build curiosity and take-up research in the field further. It is arguably a very misunderstood concept as students tend to have a complete misunderstanding of the process like inverse respiration, plants get their food from soil roots acting as their feeding organs, etc.no life can exist without photosynthesis, the carbon dioxide in the atmosphere that has a big cause of global heating can be reduced by increased photosynthesis, and an understanding of carbon recycling generates general knowledge about the chemical, geological, physical, and biological course of events. If people did know more about photosynthesis it could perhaps lead to people’s harder work for sustainable development.” (By Helena Näs, 2010 pg 12)Understanding of Photosynthesis concept is related to students’ age. The students understanding on photosynthesis concept increases during the schooling period by gradual introduction of new contents. The process of photosynthesis contains many interrelated concepts which causes conceptual understanding difficulties. If teaching is only description of process and definition of terms and concepts results in poor knowledge and leads to misconceptions. Teaching should be done progressively and experimentally with more practical examples.( Radanović,Garašić,Luksa and Dedic,2015) Works from teachers who have taught this concept and transformed their learners Teaching Photosynthesis to Eighth Graders (Cecilia Espinoza,2017). The Learning objectives include 1. Basic components required for photosynthesis: reactants (Light carbon dioxide and water), Plant parts (Leaves) and molecules(chlorophyll) and products (carbohydrates and oxygen). implemented a five-day lesson in a science class over the course of a month, once per week. Discussed on what is photosynthesis and how it is connected to life on earth. Shows videos on photosynthesis to become familiar with the process. Experimental activity was conducted which involves growing a plant under light and dark conditions with these students understand light energy promotes plant growth. Relationship between students and teachers improved, students gained scientific knowledge and importance of photosynthesis for life to sustain. Students also learnt about the options o a degree at university. Teaching to a smaller class size is more effective; Middle school students enjoy experimental based teaching; developing activities in collaboration with the teacher made the lesson more beneficial. The Teaching of Photosynthesis in Secondary School (AbdeljalilMétioui, FathiMatoussi and Louis Trudel,2016).Photosynthesis is a concept that should be taught at different level from the primary level to university. Need to analyses the history of research in photosynthesis which led to the misconception about the concept in learners. For example, Aristotle (384-322 B.C) thought that plants get the food from soil, Later physician and chemist Van Helmont (1677–1644) added to this that plants only use water for their growth. Teacher should not ignore such misconceptions in the students during teaching. This prevents students to understand the importance of chlorophyll in transforming sunlight to chemical energy. Hence teaching the history of the process of photosynthesis allows student to unlearn the misconceptions and leads to construction of knowledge. Students will have opportunity to learn new theories and do more research. The Lesson: Introduction – Engage Students in Learning In Step 1, teacher will help students to attach the thought of food-web with photosynthesis. The goal of this step is to make them understand the important role of photosynthesis plays in our ecosystem. (1) Introduction of the subject by saying: “Hello, we are getting to study photosynthesis today. Before starting the lesson, ask students does there anyone know where plants get their energy from?” (2) Teacher can prepare a feed-web (see Figure 1.) on transparency, doc cam, display screen, or draw the figure on the board. Teacher can than ask the subsequent inquiries to guide the discussion: • All living things need energy to survive. How do us, human get energy? • From this food-web (Figure 1), • From this food-web (Figure 1), how do grass and trees gain their energy from? Do grass and trees ‘eat’ any other organisms? Figure-1 (3) supported students’ response, teacher can re-voice students’ responses and write the responses on the board. (4) After students sharing their ideas about food-web, teacher can begin the category by introducing the driving question of this lesson: “Plants need energy to remain alive and grow. How do you think plants get energy?” (5) explain the definition of photosynthesis and various components required to carry out the process (6) discuss on various inputs and outputs of photosynthesis Remove all the misconceptions/preconceptions relevant to the concept of photosynthesis: • there's no difference between respiration and breathing. • The main component of air is oxygen. • There is no oxygen in exhaled air. • Lighting a candle during a sealed jar with water proves that air is 21% oxygen (the water moves up the jar because the 21 LOX is consumed). • All essential components required by plants are absorbed from the soil via roots. • Roots supply plants with energy. • The sun keeps plants warm, then they grow better. • Plants breath. They inhale carbon dioxide, and they exhale oxygen. • Plants get energy directly from the sun. Drawing Activity Start by getting the scholars to draw a flower on a bit of paper. Ask them to draw the sun, water, soil and rain. Next, get them to write down CO2 and draw an arrow towards the flower. On the other side, write the word oxygen and draw another arrow, but far away from the flower this point. At rock bottom of the plant, draw a sugar cube. Make sure to elucidate the method of photosynthesis as they're drawing as they are going along. Sunlight Experiment Give each student two paper cups with a fast-growing plant potted inside. Ask them to put one cup during a dark room and therefore the other within the sunlight on a windowsill. Each child must water both flowers throughout the week. After every week has passed, get the youngsters to bring over both their plants and ask them to observe the plant and Explain that the plant did not get sufficient sunlight within the dark room to carryout photosynthesis and as a result the plant looks limp and is dying. Photosynthesis Chemical Experiment Purchase some small plants and obtain your students to place them in test tubes crammed with water. Plug the opening of the test tubes. During subsequent few minutes, bubbles will appear on the edges of the test tubes. This is a photosynthesis chemical response that shows plants changing CO2 and water into food Assessments Give children various assessments like quiz, worksheets, writing short essay on the concept of photosynthesis to check their understanding and remove all possible misconceptions through experiential learning methods Students can better understand the concept of photosynthesis through experiential method, as students can get complete clarity on how each component is very important for a plant to carry out photosynthesis. Even though teaching photosynthesis remains one of the most challenging, largely because of a) its conceptual difficulty, leads to many misconceptions among students; b) visualising the process can be difficult , or relating it to things they can see, especially when the topic is presented purely as a molecular process; and c) practical demonstration of photosynthesis have certain limitations because equipment is either cheap, unreliable and antiquated or prohibitively expensive. Teaching the concept helps educator to think from student’s perspective and to think how it is like to be uncertain and not knowing the concept. It helps to effectively address why they have possible misconceptions and what effective methods can be followed to specifically address them. (sciences engineering medicine pg 53) Medium to teach the concept The photosynthesis can be taught in many ways and medium. Photosynthesis is a very important concept for students and for life on earth, Learners will have many misconceptions so it should be taught in more effective method. The below methods are used in teaching the process of photosynthesis. Interaction based black boarding teaching Start the class by interacting with the students to know the knowledge level of the students about the concept and the misconceptions they have about the concept. Then introduce the concept, define the concept and explain the concept in detail to students and assess them by asking the questions. Activity based teaching Organise an activity about the concept in the classroom and involve the students to participate in the activity, this helps them to understand more on the explanation given earlier. Experiment based teaching Conduct two to three experiments by the students about photosynthesis which helps to clear all misconceptions about Photosynthesis and enables the students to learn and do more research on concept. Interaction based Black board teaching and experiment-based teaching are the two strong mediums. Interaction based Black board teaching enables the teacher to know the knowledge level of the students about the concept and the misconceptions they have about the concept. Knowing this we can change the content and focus area in the concept. By regularly interacting with the students by asking questions during teaching helps the teacher to assess the students understanding on the concept and repeat or revise on the area where concept is not understood well. This helps in avoid misconceptions in students and clear all their queries in the classroom itself. Experiment based teaching enables students to understand the concept better and implement their learning in the classroom in real life. Understand the importance of Photosynthesis process for life to sustain, food cycle chain and eco-system balance. It will also clear all the misconception on the concept and encourage the students to do more research on the concept. The above two mediums of teaching are very effective to make the students understand the concept of photosynthesis. References Howard Gest 1993 https://link-springer-com.ezproxy.bcu.ac.uk/article/10.1023/A:1020419417954 Written by and Copyright ©1996 Devens Gust Professor of Chemistry and Biochemistry, Arizona State University https://live-bioenergy.ws.asu.edu/content/why-study-photosynthesis Common Misconceptions about Plants By Jessica Fries-Gaither,2009. https://beyondpenguins.ehe.osu.edu/issue/polar-plants/common-misconceptions-about-plants Secondary School Students’ Misconceptions about Photosynthesis and Plant Respiration: Preliminary Results by Katerina Svandova Masaryk University, CZECH REPUBLIC,2013 https://www.ejmste.com/download/secondary-school-students-misconceptions-aboutphotosynthesis-and-plant-respiration-preliminary-4290.pdf Teaching Photosynthesis in a Compulsory School Context by Helena Nas-2010. http://umu.diva-portal.org/smash/get/diva2:300885/FULLTEXT01.pdf Understanding of photosynthesis concepts related to students’ age‖ by Ines Radanović,DianaGarašić,ZaklinLuksa and ZrinkaRisticDedic-2015 https://www.researchgate.net/publication/303525023_Understanding_of_photosynthesis_con cepts_related_to_students'_age Teaching Photosynthesis to Eighth Graders: A Graduate Service-Learning Experience in a Local Science Class -Class Cecilia Espinoza-2017 https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1108&context=pjsl The Teaching of Photosynthesis in Secondary School: A History of the Science Approach By AbdeljalilMétioui, FathiMatoussi and Louis Trudel https://www.researchgate.net/publication/305699079_The_Teaching_of_Photosynthesis_in_ Secondary_School_A_History_of_the_Science_Approach
