Science Spotlight On... Euglena Density

Year 11 Biology students have mastered the use of light microscopes and are now applying their skills to investigate the phototaxis of Euglena sp.

Phototaxis refers to the movement of an entire organism or cell towards or away from a light source.

Euglenas are unicellular, photosynthetic microorganisms containing chloroplasts. They move using a flagellum and possess a light-sensitive eyespot that detects specific wavelengths of light, enabling them to respond to changes in their environment. Because they rely on photosynthesis to obtain energy, their ability to detect and respond to light is closely linked to maximising their energy production. Although typically photoautotrophic, they can also behave as heterotrophs by absorbing or ingesting nutrients when needed. These organisms are commonly found in ponds and other small bodies of water.

Each student designed and conducted their own investigation, manipulating either the intensity or quality of light within the microscope’s field of view and measuring changes in Euglena density.