The overwhelming majority of students thought that respiration is a gas exchange process during which oxygen is taken in and carbon dioxide is given off.
They believed that plants respire at night when there is no light energy because they make photosynthesis during the day.
Respiration occurs only in animal cells because only animal cells need energy to live was one of the most common misconceptions shared by the majority of the participants.
They were also not sure where respiration occurs in plants.
Two ideas were put forward by students concerning where respiration occurs in plant cells, namely, respiration took place in the cells of the leaves only because only leaves have special pores to exchange gas and respiration took place in the cells of the roots only because only roots need energy to absorb water.
Moreover, they thought that green plants take in carbon dioxide and give off oxygen when they respire.
Some students stated that plants respire when they cannot obtain enough energy from photosynthesis.
Furthermore, some of the participants claimed that green plants do not respire at all and that respiration occurs only in animal cells since they cannot photosynthesize to produce energy.
To sum up, participants perceived photosynthesis as an energy-providing process, did not grasp the nature and the function of respiration and photosynthesis, did not realize that respiration is an energy conversion process and energy-producing process, and consider respiration to be synonymous with breathing.