Question

How does the ability to detect light benefit the planarian?

Answer 1

The Planaria has the ability to detect the light due to the presence of eye spot. These eye spot acts as photoreceptors which are sensitive to light, so they can detect and move away from the light source.The Planaria is unable to survive under dry condition, since the light dries up their skin. So they move away from the light source to protect their skin from drying.