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.
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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).
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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.
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Appendix 2
A teaching strategy based on the constructivist principle:
(Sexual reproduction in Angiosperms)
1.
Examine the structures of flowers
(Key structures only and avoid excessive details)
Use models / wall charts / pictures to
discuss the functions of the floral structures
Concept of pollination
Examine and compare the structures of
various flowers (eg. cassia, Bauhinia)
Group discussion on the differences between
insect-pollinated and wind-pollinated flowers
Process of fertilization
Seed formation
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2.
Examine seeds with
different forms
Discussion on their
methods of dispersal
Importance of dispersal of seeds
by fruits
Structures of seed
Student activity:
suggest the conditions necessary for seed germination;
design and carry out an investigation individually by using mung bean seeds
Observe the results and conclude the
essential conditions for seed germination
Biological changes take place in
the seed during germination
Development of seedlings and
start photosynthesis
Growth of plants
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