Explain what irritability is, what causes this condition. What happens to the protozoa

Explain what irritability is, what causes this condition. What happens to the protozoa if the environment is unfavorable, for example, when the temperature drops.

Irritability is the ability of living organisms to respond to changes in their environment. This term is used both for physiological response to stimuli and for pathological, abnormal, or oversensitivity to stimuli.

This process can be explained by the example of allergies. When you are near an allergen, you can say that the body of the pollen reacts with excessive secretion of histamine, resulting in what can be called irritability in biological terms.