Student Misconception Series – Science (Part 6)
Do your Student Learn or Mug up ? Students of all ages seem to have a mind of their own when it comes to responding to any situation or performing any task. As teachers, most of us go back home thinking that our students have understood every concept that we teach them. It is only when we test them that we find that some concepts have not been understood as clearly as they should have been. It is this desire to understand student thinking that prompted us to examine ASSET questions of the past rounds, in Science, examining the most common wrong answers to understand what could have made students select the options they did.
Energy, Energy Transfer & Energy Conversion Class 7
Why was the Question asked? This question was designed to test whether students will be able to identify the appropriate set-up required to carry out the experiment based on the changes in given factors. 2. What did students answer? Around 47% of the students chose the right answer, B, whereas 21.6% chose D, a wrong answer. Possible reason for choosing B: A few students have chosen this option and are probably making a random guess. Possible reason for choosing C: Students choosing this option might think that water is essential for most living organisms and it also provides energy to them. Possible reason for choosing D: Students might be confused about the term 'energy' and may be equating the food web to a system that needs an external source of energy to run – for instance machinery in a factory that needs electricity to function.
3. Learnings Students are aware of different forms of energy like solar energy, electrical energy, etc. and they also know that living beings obtain energy from food. However, they might be unable to comprehend that living beings are storehouses of energy and that energy is transferred across different levels in a food web. In this question, students were expected to link the fact that plants make food using energy from the Sun and they are consumed by primary consumers. Other organisms obtain energy by consuming the primary consumers and so on. Hence, in this way, the entire food chain or food web ultimately gains energy from the Sun. However, only 47% of the students have chosen this answer. Some students seem to think that living organisms can obtain energy from water whereas others believe that energy is not required for the food web to function! Students should be aware of the basic fact that the energy for the sustenance of life on Earth comes from the Sun.
4. How do we handle this? Ask students if living organisms require energy. Ask them if organisms can obtain energy from any source other than the food that they consume. Discuss any doubts that the students may have. Guide them into understanding that living organisms require energy for various processes occurring in their bodies. Specify that this energy is obtained from the food that is produced (for producers) or consumed (for consumers). Ask students to think about the food that they eat. Tell them to draw a food web linking themselves as individuals within it. They should show multiple chains within the web, linking other possible consumers of plants/animals, etc. (If all the students are vegetarian, a special food web can be made for a non-vegetarian person.) Once students have designed their food webs, ask them to predict what would happen if there was no sunlight. Students should be able to predict the following by tracking their own food webs: • Without the energy provided by the Sun, there would be no primary producers (green plants) and therefore, the herbivores or the primary consumers would have no food to eat. • As animals are not able to produce their own food, irrespective of the presence of solar energy, they would not be able to obtain energy from any source and hence, would perish. • In short, life on Earth would probably perish without the energy obtained from the Sun.