Misconceptions in Biology
Misconceptions can arise in many areas of biology so it is important to consider what misconceptions might come up, how to identify them, and how to help students work through them. Using a wider range of examples and contexts can help students to overcome misconceptions and it is worth considering how you could use plant examples instead of animal ones.
This article, using content from an online course developed by SAPS and STEM Learning, looks at addressing the common misconception that plants only photosynthesise and only animals respire. We will look at some of the SAPS resources that you can use with your students to address this misconception. We will also look at how hinge point questions can be used to help you assess whether your students have overcome their misconceptions.
Approaching misconceptions with animations
The following animation shows gas exchange in a leaf in the light and in the dark.
The animation has no commentary. There are accompanying documents that can be used to explore what is being shown in each part of the animation.
Write a list of the misconceptions this animation could be used to address.
How would you then address these?
Assessing misconceptions
Having a good grasp of the misconceptions students are likely to have can help you plan meaningful assessment opportunities. When we are planning to address students’ misconceptions, we need a good set of strategies for finding out what students are thinking.
Educationalist Dylan Wiliam advocates using a well-planned, multiple-choice question which the whole class can answer, called a hinge point question. Based on the evidence from students’ responses, you can see who’s ready to move on, and who needs more support.
“When I was teaching full-time, the decision I made most often every day was this: ‘Do I need to go over this one more time, or can I move on to the next thing?’ I made that decision dozens of times every day, and like most teachers all over the world, I made that decision by asking a question.”
Dylan discusses hinge point questions in this short video.
You can also find out more about hinge point questions in this blog from the Royal Society of Chemistry.
For a ready-made set of high-quality diagnostic questions, together with the misconceptions on which they are based, take a look at BEST Evidence Science Teaching. We’ve also used some hinge point questions in the quiz further down this page.
Gathering the answers
Of course, asking the whole class a question means that you need a way of quickly collecting responses from every student. There are a range of ideas and all have benefits and limitations. Ideas include:
- Finger voting.
- Mini white boards.
- ABCD cards.
What questioning strategy do you find most useful in your teaching?
Are there any strategies which you don’t find work so well?
Tricky questions: respiration
Students can have several misconceptions about respiration. We’ve used some common misconceptions in the following quiz questions. As you do the quiz, we’d like to think about how you might deal with some of these ideas in class.
Quiz
Decide which of the responses are correct. Use the drop-down menu to check your answers…
1. Plant cells: (pick two)
a) Don’t respire, they only carry out photosynthesis.
Incorrect answer. Plants are living organisms and their cells therefore respire all the time. Not all plant cells carry out photosynthesis.
b) Respire in the dark but not in the light.
Incorrect answer. Plants are living organisms and their cells therefore respire all the time, in the light and the dark.
c) Carry out photosynthesis in the light and respire all the time.
Correct answer. Plants are living organisms and their cells therefore respire all the time. Cells in the green parts of the plant can also carry out photosynthesis in the light.
d) Can carry out photosynthesis in chloroplasts and respiration in mitochondria.
Correct answer. All plant cells contain mitochondria, the site of aerobic respiration. Cells in the green parts of the plant contain chloroplasts and can carry out photosynthesis.
2. Seeds: (pick two)
a) Are dead so their cells don’t respire.
Incorrect answer. Seeds are alive and therefore their cells will respire
b) Are alive and therefore their cells will respire.
Correct answer.
c) Are alive, but their cells don’t respire.
Incorrect answer. Seeds are alive and therefore their cells respire.
d) Are dormant and are therefore alive.
Correct answer. Dormant seeds are alive and are therefore respiring. They remain dormant until conditions become favourable for germination.
3. Aerobic Respiration: (pick two)
a) Uses glucose and oxygen and produces carbon dioxide and water.
Correct answer.
b) Uses carbon dioxide and water and produces glucose and oxygen.
Incorrect answer. Aerobic respiration uses glucose and oxygen and produces carbon dioxide and water.
c) Uses oxygen and carbon dioxide and produces glucose and water.
Incorrect answer. Aerobic respiration uses glucose and oxygen and produces carbon dioxide and water.
d) Takes place in both plant and animal cells.
Correct answer. Aerobic respiration takes place in the mitochondria. These organelles are present in both plant and animal cells.
4. On a sunny day: (pick two)
a) The rate of diffusion of carbon dioxide out of the leaf will be greater than the rate at which carbon dioxide diffuses into the leaf.
Incorrect answer. In bright sunlight, cells in the green parts of the plant will be carrying out photosynthesis at a greater rate than they will be respiring. These cells will therefore be using carbon dioxide in photosynthesis at a greater rate than they will be producing it in respiration. Carbon dioxide will therefore diffuse into the leaf, and hence into the cells in the leaf, at a greater rate than it will diffuse out of the leaf.
b) The rate of diffusion of carbon dioxide into the leaf will be greater than the rate at which carbon dioxide diffuses out of the leaf.
Correct answer. In bright sunlight, cells in the green parts of the plant will be carrying out photosynthesis at a greater rate than they will be respiring. These cells will therefore be using carbon dioxide in photosynthesis at a greater rate than they will be producing it in respiration. Carbon dioxide will therefore diffuse into the leaf, and hence into the cells in the leaf, at a greater rate than it will diffuse out of the leaf.
c) The rate of diffusion of carbon dioxide into the leaf will be the same as the rate at which carbon dioxide diffuses out of the leaf.
Incorrect answer. In bright sunlight, cells in the green parts of the plant will be carrying out photosynthesis at a greater rate than they will be respiring. These cells will therefore be using carbon dioxide in photosynthesis at a greater rate than they will be producing it in respiration. Carbon dioxide will therefore diffuse into the leaf, and hence into the cells in the leaf, at a greater rate than it will diffuse out of the leaf. If the rate of diffusion of carbon dioxide into the leaf is the same as the rate at which carbon dioxide diffuses out of the leaf, the rates of photosynthesis and respiration in the cells of the leaf must be equal.
d) The rate of diffusion of oxygen out of the leaf will be greater than the rate at which oxygen diffuses into the leaf.
Correct answer. In bright sunlight, cells in the green parts of the plant will be carrying out photosynthesis at a greater rate than they will be respiring. These cells will therefore be producing oxygen in photosynthesis at a greater rate than they will be using it in respiration. Oxygen will therefore diffuse out of the photosynthesising cells, and hence out of the leaf, at a greater rate than it will diffuse into the leaf.
Teacher’s perspective: Assessing misconceptions
Within a science lesson, it is important that opportunities to identify and address pupils’ misconceptions are built into the lesson plan. In this video, some of the strategies used by science teachers to discover and work through their pupils’ misconceptions are discussed.
How do you create opportunities for dialogue in class so that you can listen for students’ misconceptions?
Challenging misconceptions with practical work
Practical work can help to identify and address misconceptions that your pupils may have. It can also present opportunities to assess whether their misconceptions have been overcome. We will now consider some examples.
Gas exchange in plants
As you watch this video, think about misconceptions the students may have about gas exchange in plants.
You can find out how to make algal balls using the video and teaching, technical and student resources here.
While you were watching the algal balls practical investigation you considered the misconceptions which students might have.
Try devising a diagnostic (hinge point) question which would probe your students understanding of the key concepts that the practical addresses.
Conclusion
Practical investigations and group discussions are invaluable tools that can help you and your pupils identify and address misconceptions in biology. Readily available plant material can enable practical investigations to be carried out throughout the school year. Carefully planned assessment can then be used to decide whether a misconception has been successfully challenged and overcome.
This article was written using reworked content from the course Teaching Biology: Inspiring Students with Plant Science codeveloped by SAPS and STEM Learning.
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