In response to a stressful work deadline, jonas' heart rate increased and blood raced to his skeletal muscles. these physical reactions best characterize the phase of the

The right answer is the first phase of the general adaption syndrome.

The concept of stress was introduced by Hans Selye. He describes the mechanism of the adaptation syndrome, that is to say all the modifications that allow an organism to bear the consequences of a natural or operative trauma.

In fact, it is the double-perception of a state of divergence between a demand for adaptation at a given moment and the ability to cope with it. It is an energy expenditure. It can be positive or negative.

The stress syndrome evolves in three successive stages:

*"Alarm reaction": the defense forces are mobilized

*"Resistance stage": adaptation to the stressor

*"Stage of exhaustion": inexorably reached if the stressor is sufficiently powerful and acts a long time.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c