Answer:
The correct answer is : nervous system.
Explanation:
Irritability is one of the key aspect life which is deal with being able to response or change according to the stimuli that is occur and disturbs the homeostasis of the body which is maintaining the body environment for living.
Nervous system is deal with the irritability by sensing the stimuli in which change occur it can be physical stimuli such as temperature, light, or sound or chemical stimuli such as pH, ions, amount of required chemical or biological stimuli such microbes in body. All these stimuli are sense b the sensory neurons and then send these signals to brain or spinal cord in order t act and respond accordingly to maintain homeostasis.
Thus, the correct answer is : nervous sytem.
Circadian rhythms ....its just behavior that is repeated over 24 hours
These are called Temperate zones because of the variety in temperatures throughout the year and the more distinct seasonal changes
Temp causes water to rise or sink through convection, and salinity affects the density of the water, so higher salinity water will contribute to deep water currents