Compare and contrast the digestive system of amoeba and planaria​

Amoeba is unicellular and is very primitive compared to planaria.

Planaria is advance and evolurionary, stands at a higher level being included in flatworms.

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms