Cells and DNA

Two teachers, Mrs Raj and Mr Mong, aroused their students' interest in the topic of cells and DNA by having them conduct an experiment about extracting DNA from crushed strawberries.

Briefly, the experiment involved smashing strawberries, adding extraction liquid (made of detergent, salt, and water), filtering the mixture, and adding rubbing alcohol to the filtered strawberry liquid. The resulting white precipitate/residue (strawberry DNA) that appeared on top of the strawberry mixture (Fig. 1) triggered student's curiosity as to what it was.

 Fig. 1. Result of the strawberry DNA experiment.

Fig. 1. Result of the strawberry DNA experiment.

The following lesson, the teachers initiated and facilitated discussions on KF with their respective classes (Figs. 2 & 3). There were plenty of initial questions regarding the experiment, which were built on and improved, such that students' discussions on KF in consequent lessons revolved around the main concept of cells and its functions.

 Fig. 2. Class 1A KF view 'Cells and DNA'.

Fig. 2. Class 1A KF view 'Cells and DNA'.

 Fig. 3. Class 1B KF view 'Cells and DNA'

Fig. 3. Class 1B KF view 'Cells and DNA'