A teaching strategy to deal with students’ misconception

that light is a necessary condition for seed germination

By :Tsoi Kwok Wing, Addis

A teaching strategy to deal with students’ misconception

of light is necessary for the germination of seeds.

When Form 5 students are asked what conditions are essential for the seed germination, some of the students may say “air(oxygen)”, some may say “water” or “warm temperature”. However, many students are likely to have such a misconception that light is an essential factor for the germination of seeds.

No matter the concept of seed germination has been taught or not in biology lessons, many students may still have this misconception. Moreover, this misconception does not only come from the average-ability groups, but also from a considerable number of students of the higher ranks. What are the causes for their erroneous view?

The misconception is unlikely due to the inadequate subject knowledge of a teacher. In my opinion, this is mainly propagated by some other factors. Students lacking of prerequisite knowledge or having informal preconceptions is one of the factors. Besides, the emphasis on excessive details including many biological terms and facts is also an important cause as this require students for rote learning instead of motivation and interest-arousing. On the other hand, the compartmentalisation of concepts and the traditional teaching sequence recommended in the syllabus or the textbook approach also lead to little integration between different processes and knowledge.

To overcome the above problems, new teaching strategy should be designed and applied in order to rectify the misconception or prevent its development during learning.

The traditional teaching method may make the students confuse about the concepts of two processes : photosynthesis and seed germination. Many students think that seed germination is one of the stages in the development or plant growth. From their previous knowledge learned in a separate chapter of autotrophic nutrition, they comprehend that photosynthesis, in most cases, is the main or even unique way for the growth of plants. Furthermore, many students know that seed contains cotyledons (in Chinese:子葉) , but they also misunderstand that “cotyledon is a leaf containing chlorophyll which is the point for the start of photosynthesis and make the seed germinate”. As light is needed in photosynthesis, they confuse with the factors necessary for photosynthesis and the conditions necessary for seed germination. These result in a misconception that light is an essential condition in the latter process.

After the analysis of the causes, the little integration between the processes is the main problem. Therefore the sequences of the processes should be clearly clarified at the beginning of the lesson, starting from pollination, and then fertilization, seed dispersal, seed germination, photosynthesis and growth.

In my designed teaching strategy, before teaching seed germination, clarifying the whole sequences is the first step so that students can establish a meaningful relationship between the processes. Then make a revision of the structures of seeds. Emphasis should be put on the role of cotyledons in the seeds are important as this may avoid the students to misunderstand that the cotyledons in this stage can proceed photosynthesis to make food for germination. The biochemical changes take places inside the food storage of cotyledons during germination (i.e. starch  sugars; proteins  peptides / amino acids) are not necessarily arranged to be taught at this stage. Because this easily mislead the students to have an erroneous view that cotyledon starts the germination of seeds by means of photosynthesis where light is needed.

To further strengthen the correct concept of water, oxygen and suitable temperature are the three conditions necessary for germination of seeds and to avoid the misconception of contribution of light to the seed germination to appear, intensive activity can be carried out by students themselves.

About one week before the related practical lessons, teachers can guide the students to think about what conditions are necessary for seed germination. Their answers may be right or wrong. However, the teacher do not make a conclusion, instead, guide them or instruct them (Appendix 1) to design and carry out an investigation themselves to determine which suggested conditions are necessary. The teacher can provide some materials required (eg. mung beans) for them to try to make the seeds germinate at home. If necessary, limited guidelines can be given in order to prevent anomalous results. Throughout the investigation, students can be motivated to investigate the problems and they also learn how to deal with problems met as well as developing an interest in planting. However, the main target of this student activity is to rectify or prevent the development of the misconception of light being a necessary condition for seed germination.

The students are required to bring their “plants” back to school in the coming practical lessons. During the lessons, students are encouraged to observe the results of the other students / groups, discuss and conclude which conditions are essential. Afterwards, the teacher can continue his / her designated teaching sequences (Appendix 2).

A summary or revision of the main points taught is sometimes useful in the closure of the lesson to reinforce the effect. It is helpful for the teacher to discuss the differences between photosynthesis and seed germination again if necessary to minimize the chances for getting misconception. The fact that light can stimulate the synthesis of chlorophyll in the leaves but not start germination of seeds should also be emphasized again. Finally, those students failed in germinating the seeds are advised to try to make all the seeds germinated again.

Although the above teaching strategy aims at preventing the development of misconception during learning, it is possible that some students still fail to avoid getting the misconception. This is likely due to their personal problems and is difficult to cope with even by other strategies. If happens, ask them to complete the exercises on the worksheets given or give extra homework for them is unavoidably a remedial method.

In conclusion, the above teaching strategy based on constructivist principles that enhance conceptual formation and development. This is meaningful and deserved to be applied on the teaching process in an attempt to deal with the students’ misconception.

Appendix 2

A teaching strategy based on the constructivist principle:

(Sexual reproduction in Angiosperms)

1.

2.

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